diff --git a/backend/.gitignore b/backend/.gitignore
new file mode 100644
index 0000000..5a87672
--- /dev/null
+++ b/backend/.gitignore
@@ -0,0 +1,30 @@
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# Virtual environments
+venv/
+env/
+.venv/
+
+# IDE specific files
+.vscode/
+.idea/
+
+# Environment variables
+.env
+.env.local
+
+# Logs and databases
+*.log
+*.sqlite3
+
+# Testing
+.coverage
+htmlcov/
+
+# Python packaging
+*.egg-info/
+dist/
+build/
diff --git a/backend/config.py b/backend/config.py
new file mode 100644
index 0000000..26c2986
--- /dev/null
+++ b/backend/config.py
@@ -0,0 +1,35 @@
+import os
+from datetime import timedelta
+
+# 数据库配置
+DATABASE_CONFIG = {
+    'host': os.getenv('DB_HOST', 'localhost'),
+    'port': int(os.getenv('DB_PORT', '3306')),
+    'user': os.getenv('DB_USER', 'root'),
+    'password': os.getenv('DB_PASSWORD', 'password'),
+    'database': os.getenv('DB_NAME', 'user_manage'),
+    'charset': 'utf8mb4'
+}
+
+# JWT配置
+JWT_CONFIG = {
+    'secret_key': os.getenv('JWT_SECRET_KEY', 'your-secret-key'),
+    'algorithm': 'HS256',
+    'access_token_expire': timedelta(minutes=int(os.getenv('JWT_ACCESS_EXPIRE_MINUTES', '10'))),
+    'refresh_token_expire': timedelta(days=int(os.getenv('JWT_REFRESH_EXPIRE_DAYS', '3')))
+}
+
+# 日志配置
+LOGGING_CONFIG = {
+    'level': os.getenv('LOG_LEVEL', 'INFO'),
+    'format': '%(asctime)s - %(name)s - %(levelname)s - %(message)s',
+    'filename': os.getenv('LOG_FILE', 'app.log')
+}
+
+# 系统管理员初始配置
+SYSTEM_ADMIN_CONFIG = {
+    'username': os.getenv('ADMIN_USERNAME', 'admin'),
+    'password': os.getenv('ADMIN_PASSWORD', 'password'),
+    'role': os.getenv('ADMIN_ROLE', 'system_admin'),
+    'description': os.getenv('ADMIN_DESCRIPTION', 'default system admin')
+}
diff --git a/backend/devdoc.md b/backend/devdoc.md
new file mode 100644
index 0000000..0e05f84
--- /dev/null
+++ b/backend/devdoc.md
@@ -0,0 +1,109 @@
+## 项目概述
+
+本项目是一个简单的用户管理系统，支持三种用户角色：系统管理员、管理员和普通用户。系统管理员在项目启动时自动生成，且唯一。所有账户必须由管理员手动创建。用户表包含密码、ID、角色、描述等信息，管理员可以对用户表进行增删改查，普通用户只能读取用户表。
+
+## 技术栈
+
+* **后端技术栈**：FastAPI、SQLAlchemy、MySQL、bcrypt、PyJWT、logging
+* **前端技术栈**：Vue、Vue Router、Pinia、Vite、Axios、Element Plus
+
+## 数据库设计
+
+### 用户表结构
+
+| 字段名 | 数据类型 | 约束条件 | 默认值 | 说明                                               |
+| -------- | ---------- | ---------- | -------- | ---------------------------------------------------- |
+| `id`       | `INT`         | `PRIMARY KEY`, `AUTO_INCREMENT`       | -      | 用户ID，主键，自增                                 |
+| `username`       | `VARCHAR(50)`         | `NOT NULL`, `UNIQUE`       | -      | 用户名，唯一                                       |
+| `password`       | `VARCHAR(255)`         | `NOT NULL`         | -      | 用户密码，使用哈希加密存储                         |
+| `role`       | `ENUM`         | `NOT NULL`         | `UserRole.USER`       | 用户角色，枚举类型，可选值为 `UserRole.SYSTEM_ADMIN`, `UserRole.ADMIN`, `UserRole.USER`                  |
+| `description`       | `TEXT`         | -        | -      | 用户描述，可选                                     |
+| `created_at`       | `DATETIME`         | -        | `当前UTC时间`       | 用户创建时间，默认值为当前UTC时间                     |
+| `updated_at`       | `DATETIME`         | -        | `当前UTC时间，更新时自动更新`       | 用户信息更新时间，默认值为当前UTC时间，更新时自动更新 |
+
+### 数据库初始化
+
+* 系统初始化时，后端控制层会检查表是否存在，若不存在则自动创建表。
+* 检查表中是否存在系统管理员，若不存在则创建一个名为`admin`、密码为`password`、描述为`default system admin`的系统管理员。
+
+## 鉴权设计
+
+### 角色权限
+
+* **系统管理员、管理员**：可以访问所有 API，包括用户增删改查。
+* **普通用户**：只能访问用户列表（只读）。
+
+### JWT 鉴权
+
+JWT（JSON Web Token）用于用户身份验证和权限控制。JWT 包含以下信息：
+
+* **Payload**：用户 ID、用户名、角色、Token 过期时间、token_type等。
+* **签名**：使用后端密钥对 Payload 进行签名，确保 Token 的完整性和安全性。
+
+### JWT Token 数据结构
+
+```python
+class TokenPayload:
+    id: int  # 用户ID
+    username: str  # 用户名
+    role: str  # 用户角色
+    exp: int  # Token过期时间
+    token_type: str  # Token类型（access或refresh）
+```
+
+### JWT 自动过期机制
+
+* **Access Token**：用于常规 API 请求，有效期较短（如 30 分钟）。
+* **Refresh Token**：用于刷新 Access Token，有效期较长（如 7 天）。
+
+#### Token 刷新流程
+
+1. 客户端使用 Refresh Token 请求 `/api/auth/refresh` 接口。
+2. 服务端验证 Refresh Token 的有效性。
+3. 服务端生成新的 Access Token 和 Refresh Token，并返回给客户端。
+4. 客户端更新本地存储的 Token。
+
+### Token 验证
+
+* **verify_access_token**：验证access token有效性并返回payload，如果token无效或类型不匹配则返回None
+* **verify_refresh_token**：验证refresh token有效性并返回payload，如果token无效或类型不匹配则返回None
+
+## 单元测试
+
+### 测试框架
+
+* 使用 `pytest` 进行单元测试。
+* 使用 `requests` 库模拟 API 请求。
+
+### 测试用例
+
+1. **用户登录**：
+    * 测试正确的用户名和密码。
+    * 测试错误的用户名和密码。
+2. **用户登出**：
+    * 测试已登录用户登出。
+    * 测试未登录用户登出。
+3. **刷新 JWT Token**：
+    * 测试有效的 Refresh Token。
+    * 测试无效的 Refresh Token。
+4. **获取用户列表**：
+    * 测试不同角色的用户访问权限。
+    * 测试分页和过滤功能。
+5. **创建用户**：
+    * 测试管理员创建用户。
+    * 测试普通用户尝试创建用户。
+6. **更新用户信息**：
+    * 测试管理员更新用户信息。
+    * 测试普通用户尝试更新用户信息。
+7. **删除用户**：
+    * 测试管理员删除用户。
+    * 测试普通用户尝试删除用户。
+
+## 日志记录
+
+* 使用 `logging` 模块记录系统日志。
+* 日志级别包括 `INFO`、`WARNING`、`ERROR`。
+* 日志内容包括用户操作、API 请求、错误信息等。
+
+## 后续开发
+* **部署文档**：包括 Docker 容器化、CI/CD 流程、环境变量配置等。
\ No newline at end of file
diff --git a/backend/main.py b/backend/main.py
new file mode 100644
index 0000000..6a9e6f6
--- /dev/null
+++ b/backend/main.py
@@ -0,0 +1,47 @@
+from dotenv import load_dotenv
+load_dotenv()
+
+import logging
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from config import JWT_CONFIG, LOGGING_CONFIG, SYSTEM_ADMIN_CONFIG
+from services.db import create_db_engine, init_db, close_db_connection
+from routes.auth import router as auth_router
+from routes.users import router as users_router
+
+# 配置日志
+logging.basicConfig(
+    level=LOGGING_CONFIG['level'],
+    format=LOGGING_CONFIG['format'],
+    filename=LOGGING_CONFIG['filename']
+)
+logger = logging.getLogger(__name__)
+
+# 初始化FastAPI应用
+app = FastAPI(
+    title="User Management System",
+    description="API for managing users with role-based access control",
+    version="1.0.0"
+)
+
+# 数据库初始化
+@app.on_event("startup")
+async def startup_event():
+    logger.info("Initializing database...")
+    engine = create_db_engine()
+    await init_db(engine)
+    logger.info("Database initialized successfully")
+
+@app.on_event("shutdown")
+async def shutdown_event():
+    logger.info("Closing database connections...")
+    await close_db_connection()
+    logger.info("Database connections closed")
+
+# 注册路由
+app.include_router(auth_router, prefix="/api/auth", tags=["auth"])
+app.include_router(users_router, prefix="/api/users", tags=["users"])
+
+if __name__ == "__main__":
+    import uvicorn
+    uvicorn.run(app, host="0.0.0.0", port=8000)
diff --git a/backend/models/__init__.py b/backend/models/__init__.py
new file mode 100644
index 0000000..35b01f3
--- /dev/null
+++ b/backend/models/__init__.py
@@ -0,0 +1,3 @@
+from .user import User
+
+__all__ = ["User"]
diff --git a/backend/models/user.py b/backend/models/user.py
new file mode 100644
index 0000000..e36e3dd
--- /dev/null
+++ b/backend/models/user.py
@@ -0,0 +1,25 @@
+from datetime import datetime, timezone
+from enum import Enum
+from sqlalchemy import Column, Integer, String, Text, DateTime, Enum as SQLEnum
+from sqlalchemy.ext.declarative import declarative_base
+
+Base = declarative_base()
+
+class UserRole(str, Enum):
+    SYSTEM_ADMIN = "system_admin"
+    ADMIN = "admin"
+    USER = "user"
+
+class User(Base):
+    __tablename__ = "users"
+
+    id = Column(Integer, primary_key=True, autoincrement=True)
+    username = Column(String(50), unique=True, nullable=False)
+    password = Column(String(255), nullable=False)
+    role = Column(SQLEnum(UserRole), nullable=False, default=UserRole.USER)
+    description = Column(Text)
+    created_at = Column(DateTime, default=lambda: datetime.now(timezone.utc))
+    updated_at = Column(DateTime, default=lambda: datetime.now(timezone.utc), onupdate=lambda: datetime.now(timezone.utc))
+
+    def __repr__(self):
+        return f"<User(id={self.id}, username={self.username}, role={self.role})>"
diff --git a/backend/requirements.txt b/backend/requirements.txt
new file mode 100644
index 0000000..acec49f
--- /dev/null
+++ b/backend/requirements.txt
@@ -0,0 +1,9 @@
+fastapi>=0.95.2
+python-dotenv>=1.0.0
+sqlalchemy>=2.0.15
+passlib>=1.7.4
+bcrypt>=4.0.1
+pyjwt>=2.6.0
+pytest>=7.3.1
+requests>=2.28.2
+uvicorn[standard]>=0.21.1
diff --git a/backend/routes/auth.py b/backend/routes/auth.py
new file mode 100644
index 0000000..3ad1498
--- /dev/null
+++ b/backend/routes/auth.py
@@ -0,0 +1,32 @@
+from fastapi import APIRouter, Depends, HTTPException
+from fastapi.security import OAuth2PasswordBearer
+from sqlalchemy.ext.asyncio import AsyncSession
+from schemas.auth import TokenResponse, LoginRequest, RefreshTokenRequest
+from services.auth import create_tokens_response, refresh_tokens
+from services.user import authenticate_user
+from services.db import get_db_session_dep
+
+router = APIRouter(tags=["auth"])
+oauth2_scheme = OAuth2PasswordBearer(tokenUrl="token")
+
+@router.post("/login", response_model=TokenResponse)
+async def login(
+    login_data: LoginRequest,
+    session: AsyncSession = Depends(get_db_session_dep)
+):
+    user = await authenticate_user(session, login_data.username, login_data.password)
+    if not user:
+        raise HTTPException(
+            status_code=401,
+            detail="Invalid username or password",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+    return create_tokens_response(user.id, user.username, user.role)
+
+
+@router.post("/refresh", response_model=TokenResponse)
+async def refresh_token(refresh_data: RefreshTokenRequest):
+    tokens = refresh_tokens(refresh_data.refresh_token)
+    if not tokens:
+        raise HTTPException(status_code=401, detail="Invalid refresh token")
+    return tokens
diff --git a/backend/routes/depends.py b/backend/routes/depends.py
new file mode 100644
index 0000000..9fa5edb
--- /dev/null
+++ b/backend/routes/depends.py
@@ -0,0 +1,34 @@
+from fastapi import Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordBearer
+from typing import Optional
+from schemas.auth import TokenPayload
+from schemas.user import UserRole
+from services.auth import verify_access_token
+
+oauth2_scheme = OAuth2PasswordBearer(tokenUrl="auth/login")
+
+async def _get_token_data(token: str) -> TokenPayload:
+    """验证并返回TokenData"""
+    token_data = verify_access_token(token)
+    if token_data is None:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Invalid or expired authentication credentials",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+    return token_data
+
+async def get_current_user(token: str = Depends(oauth2_scheme)) -> TokenPayload:
+    """获取当前用户"""
+    return await _get_token_data(token)
+
+async def get_current_admin(token: str = Depends(oauth2_scheme)) -> TokenPayload:
+    """获取当前管理员用户"""
+    token_data = await _get_token_data(token)
+    if token_data.role not in [UserRole.SYSTEM_ADMIN, UserRole.ADMIN]:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Access denied: Insufficient privileges for this operation",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+    return token_data
\ No newline at end of file
diff --git a/backend/routes/users.py b/backend/routes/users.py
new file mode 100644
index 0000000..72f47d9
--- /dev/null
+++ b/backend/routes/users.py
@@ -0,0 +1,69 @@
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.ext.asyncio import AsyncSession
+from typing import List, Optional
+from schemas.auth import TokenPayload
+from schemas.user import UserCreate, UserUpdate, UserResponse, UserRole
+from routes.depends import get_current_user,get_current_admin
+import services.user as user_service
+
+from services.db import get_db_session_dep
+
+router = APIRouter(tags=["users"])
+
+@router.get("/", response_model=List[UserResponse])
+async def get_users_list(
+    page: int = 1,
+    limit: int = 100,
+    role: Optional[str] = None,
+    current_user_token: TokenPayload = Depends(get_current_user),
+    session: AsyncSession = Depends(get_db_session_dep)
+):
+    skip = (page - 1) * limit
+    users = await user_service.get_users_list(session, skip=skip, limit=limit)
+    if role:
+        users = [user for user in users if user.role == role]
+    return users
+
+@router.post("/", response_model=UserResponse, status_code=status.HTTP_201_CREATED)
+async def create_user(
+    user_data: UserCreate,
+    current_user_token: TokenPayload = Depends(get_current_admin),
+    session: AsyncSession = Depends(get_db_session_dep)
+):
+    return await user_service.create_user(session, user_data)
+
+@router.put("/{user_id}", response_model=UserResponse)
+async def update_user(
+    user_id: int,
+    user_data: UserUpdate,
+    current_user_token: TokenPayload = Depends(get_current_admin),
+    session: AsyncSession = Depends(get_db_session_dep)
+):
+    return await user_service.update_user(session, user_id, user_data)
+
+@router.get("/{user_id}", response_model=UserResponse)
+async def get_user(
+    user_id: int,
+    current_user_token: TokenPayload = Depends(get_current_user),
+    session: AsyncSession = Depends(get_db_session_dep)
+):
+    user = await user_service.get_user(session, user_id)
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="User not found"
+        )
+    return user
+
+@router.delete("/{user_id}", status_code=status.HTTP_204_NO_CONTENT)
+async def delete_user(
+    user_id: int,
+    current_user_token: TokenPayload = Depends(get_current_admin),
+    session: AsyncSession = Depends(get_db_session_dep)
+):
+    success = await user_service.delete_user(session, user_id)
+    if not success:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="User not found"
+        )
diff --git a/backend/schemas/auth.py b/backend/schemas/auth.py
new file mode 100644
index 0000000..67fe815
--- /dev/null
+++ b/backend/schemas/auth.py
@@ -0,0 +1,22 @@
+from pydantic import BaseModel
+
+class TokenResponse(BaseModel):
+    access_token: str
+    refresh_token: str
+    token_type: str
+    access_token_exp: int
+    refresh_token_exp: int
+
+class TokenPayload(BaseModel):
+    id: int
+    username: str
+    role: str
+    exp: int
+    token_type: str
+
+class LoginRequest(BaseModel):
+    username: str
+    password: str
+
+class RefreshTokenRequest(BaseModel):
+    refresh_token: str
diff --git a/backend/schemas/user.py b/backend/schemas/user.py
new file mode 100644
index 0000000..46dc5f3
--- /dev/null
+++ b/backend/schemas/user.py
@@ -0,0 +1,43 @@
+from datetime import datetime
+from enum import Enum
+from pydantic import BaseModel, Field, root_validator
+from typing import Optional
+
+# 用户角色枚举
+class UserRole(str, Enum):
+    SYSTEM_ADMIN = "system_admin"
+    ADMIN = "admin"
+    USER = "user"
+
+# 基础用户模型
+class UserBase(BaseModel):
+    username: str = Field(..., max_length=50, description="用户名")
+    role: UserRole = Field(default=UserRole.USER, description="用户角色")
+    description: Optional[str] = Field(None, max_length=255, description="用户描述")
+
+# 用户创建模型
+class UserCreate(UserBase):
+    password: str = Field(..., min_length=6, max_length=255, description="用户密码")
+
+
+# 用户更新模型
+class UserUpdate(BaseModel):
+    username: Optional[str] = Field(None, max_length=50, description="用户名")
+    role: Optional[UserRole] = Field(None, description="用户角色")
+    description: Optional[str] = Field(None, max_length=255, description="用户描述")
+
+    # 可选：确保至少更新一个字段
+    @root_validator
+    def validate_at_least_one_field(cls, values):
+        if not any(values.values()):
+            raise ValueError("至少需要更新一个字段")
+        return values
+
+# 用户响应模型
+class UserResponse(UserBase):
+    id: int = Field(..., description="用户ID")
+    created_at: datetime = Field(..., description="创建时间")
+    updated_at: datetime = Field(..., description="更新时间")
+
+    class Config:
+        orm_mode = True  # 允许从 ORM 对象加载数据
\ No newline at end of file
diff --git a/backend/services/auth.py b/backend/services/auth.py
new file mode 100644
index 0000000..32c64fd
--- /dev/null
+++ b/backend/services/auth.py
@@ -0,0 +1,90 @@
+from typing import Optional
+import jwt
+import time
+from config import JWT_CONFIG
+from schemas.auth import TokenResponse, TokenPayload
+
+SECRET_KEY = JWT_CONFIG['secret_key']
+ALGORITHM = JWT_CONFIG['algorithm']
+ACCESS_TOKEN_EXPIRE = JWT_CONFIG['access_token_expire']
+REFRESH_TOKEN_EXPIRE = JWT_CONFIG['refresh_token_expire']
+
+
+def get_current_time() -> int:
+    """获取当前UTC时间戳"""
+    return int(time.time())
+
+def create_token(user_id: int, username: str, role: str, token_type: str = "access") -> str:
+    """创建JWT token"""
+    expire_delta = ACCESS_TOKEN_EXPIRE if token_type == "access" else REFRESH_TOKEN_EXPIRE
+    expire = get_current_time() + int(expire_delta.total_seconds())
+    
+    to_encode = {
+        "id": user_id,
+        "username": username,
+        "role": role,
+        "exp": expire,
+        "token_type": token_type
+    }
+    return jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
+
+def create_tokens_response(user_id: int, username: str, role: str) -> TokenResponse:
+    """创建access token和refresh token"""
+    access_token = create_token(user_id, username, role, "access")
+    refresh_token = create_token(user_id, username, role, "refresh")
+    
+    # 获取token的过期时间
+    access_token_exp = get_current_time() + int(ACCESS_TOKEN_EXPIRE.total_seconds())
+    refresh_token_exp = get_current_time() + int(REFRESH_TOKEN_EXPIRE.total_seconds())
+    
+    return TokenResponse(
+        access_token=access_token,
+        refresh_token=refresh_token,
+        token_type="bearer",
+        access_token_exp=access_token_exp,
+        refresh_token_exp=refresh_token_exp
+    )
+
+def verify_access_token(token: str) -> Optional[TokenPayload]:
+    """验证access token有效性并返回payload，如果token无效或类型不匹配则返回None"""
+    try:
+        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
+        if payload.get("token_type") != "access":
+            return None
+        return TokenPayload(
+            id=payload.get("id"),
+            username=payload.get("username"),
+            role=payload.get("role"),
+            exp=payload.get("exp"),
+            token_type=payload.get("token_type")
+        )
+    except (jwt.ExpiredSignatureError, jwt.InvalidTokenError):
+        return None
+
+def verify_refresh_token(token: str) -> Optional[TokenPayload]:
+    """验证refresh token有效性并返回payload，如果token无效或类型不匹配则返回None"""
+    try:
+        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
+        if payload.get("token_type") != "refresh":
+            return None
+        return TokenPayload(
+            id=payload.get("id"),
+            username=payload.get("username"),
+            role=payload.get("role"),
+            exp=payload.get("exp"),
+            token_type=payload.get("token_type")
+        )
+    except (jwt.ExpiredSignatureError, jwt.InvalidTokenError):
+        return None
+
+def refresh_tokens(refresh_token: str) -> Optional[TokenResponse]:
+    """使用refresh token刷新access token，如果refresh token无效则返回None"""
+    token_data = verify_refresh_token(refresh_token)
+    if token_data is None:
+        return None
+    else:
+        return create_tokens_response(
+            user_id=token_data.id,
+            username=token_data.username,
+            role=token_data.role
+        )
diff --git a/backend/services/db.py b/backend/services/db.py
new file mode 100644
index 0000000..eda231f
--- /dev/null
+++ b/backend/services/db.py
@@ -0,0 +1,77 @@
+from sqlalchemy.ext.asyncio import AsyncEngine, create_async_engine, AsyncSession
+from sqlalchemy.orm import sessionmaker
+from models.user import Base, User, UserRole
+from sqlalchemy import select
+from contextlib import asynccontextmanager
+from config import SYSTEM_ADMIN_CONFIG, DATABASE_CONFIG
+from services.user import get_password_hash
+from typing import AsyncGenerator
+
+# 全局数据库引擎实例
+_engine: AsyncEngine | None = None
+
+def create_db_engine() -> AsyncEngine:
+    """创建数据库引擎"""
+    return create_async_engine(
+        f"mysql+asyncmy://{DATABASE_CONFIG['user']}:{DATABASE_CONFIG['password']}@"
+        f"{DATABASE_CONFIG['host']}:{DATABASE_CONFIG['port']}/{DATABASE_CONFIG['database']}",
+        echo=True
+    )
+
+def get_db_engine() -> AsyncEngine:
+    """获取全局数据库引擎实例"""
+    if _engine is None:
+        raise RuntimeError("Database engine not initialized")
+    return _engine
+
+async def get_db_session() -> AsyncSession:
+    """获取数据库会话"""
+    async with AsyncSession(get_db_engine()) as session:
+        try:
+            yield session
+            await session.commit()
+        except Exception:
+            await session.rollback()
+            raise
+
+async def get_db_session_dep() -> AsyncSession:
+    """FastAPI依赖注入使用的数据库会话获取函数"""
+    async with AsyncSession(get_db_engine()) as session:
+        try:
+            yield session
+            await session.commit()
+        except Exception:
+            await session.rollback()
+            raise
+
+async def init_db(engine: AsyncEngine):
+    """初始化数据库"""
+    global _engine
+    _engine = engine
+    
+    async with engine.begin() as conn:
+        # 创建所有表
+        await conn.run_sync(Base.metadata.create_all)
+
+    async with AsyncSession(engine) as session:
+        # 检查系统管理员是否存在
+        result = await session.execute(
+            select(User).where(User.role == UserRole.SYSTEM_ADMIN)
+        )
+        if not result.scalars().first():
+            # 创建默认系统管理员
+            admin = User(
+                username=SYSTEM_ADMIN_CONFIG['username'],
+                password=get_password_hash(SYSTEM_ADMIN_CONFIG['password']),
+                role=UserRole.SYSTEM_ADMIN,
+                description=SYSTEM_ADMIN_CONFIG['description']
+            )
+            session.add(admin)
+            await session.commit()
+
+async def close_db_connection():
+    """关闭数据库连接"""
+    global _engine
+    if _engine is not None:
+        await _engine.dispose()
+        _engine = None
diff --git a/backend/services/user.py b/backend/services/user.py
new file mode 100644
index 0000000..c432427
--- /dev/null
+++ b/backend/services/user.py
@@ -0,0 +1,74 @@
+from typing import List, Optional
+from sqlalchemy import select, update, delete
+from sqlalchemy.ext.asyncio import AsyncSession
+from passlib.context import CryptContext
+from models.user import User
+from schemas.user import UserCreate, UserUpdate, UserResponse
+
+# 创建一个密码上下文对象，指定使用 bcrypt 加密算法
+pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
+    
+async def create_user(session: AsyncSession, user_data: UserCreate) -> UserResponse:
+    """创建用户"""
+    hashed_password = pwd_context.hash(user_data.password)
+    user = User(
+        username=user_data.username,
+        password=hashed_password,
+        role=user_data.role,
+        description=user_data.description
+    )
+    session.add(user)
+    await session.commit()
+    await session.refresh(user)
+    return UserResponse.from_orm(user)
+
+
+async def get_user(session: AsyncSession, user_id: int) -> Optional[UserResponse]:
+    """根据ID获取用户"""
+    result = await session.execute(select(User).where(User.id == user_id))
+    user = result.scalars().first()
+    return UserResponse.from_orm(user) if user else None
+
+
+async def get_users_list(session: AsyncSession, skip: int = 0, limit: int = 100) -> List[UserResponse]:
+    """获取用户列表"""
+    result = await session.execute(select(User).offset(skip).limit(limit))
+    users = result.scalars().all()
+    return [UserResponse.from_orm(user) for user in users]
+
+
+async def update_user(session: AsyncSession, user_id: int, user_data: UserUpdate) -> Optional[UserResponse]:
+    """更新用户信息"""
+    await session.execute(
+        update(User)
+        .where(User.id == user_id)
+        .values(**user_data.dict(exclude_unset=True))
+    )
+    await session.commit()
+    return await get_user(session, user_id)
+
+
+async def delete_user(session: AsyncSession, user_id: int) -> bool:
+    """删除用户"""
+    result = await session.execute(delete(User).where(User.id == user_id))
+    await session.commit()
+    return result.rowcount > 0
+
+
+def verify_password(plain_password: str, hashed_password: str) -> bool:
+    """验证输入的明文密码是否与存储的哈希密码匹配"""
+    return pwd_context.verify(plain_password, hashed_password)
+
+def get_password_hash(password: str) -> str:
+    """生成使用 bcrypt 的密码哈希"""
+    return pwd_context.hash(password)
+
+async def authenticate_user(session: AsyncSession, username: str, password: str) -> Optional[UserResponse]:
+    """验证用户登录"""
+    result = await session.execute(select(User).where(User.username == username))
+    user = result.scalars().first()
+    if not user:
+        return None
+    if not verify_password(password, user.password):
+        return None
+    return UserResponse.from_orm(user)