diff --git a/.env.example b/.env.example
index 41d1ccf..c62ab75 100644
--- a/.env.example
+++ b/.env.example
@@ -13,6 +13,13 @@ RUNTIME_MEMORY_BACKEND=redis
 REDIS_URL=redis://localhost:6379/0
 RUNTIME_MEMORY_TTL_SECONDS=7200
 
+# Django user center auth for frontend integration
+AUTH_VALIDATE_ENABLED=false
+AUTH_USER_ME_URL=http://192.168.2.76:8000/api/user/users/me/
+AUTH_TIMEOUT_SECONDS=5
+AUTH_CACHE_TTL_SECONDS=300
+AUTH_ALLOW_DEMO_USER_ID=true
+
 # OpenAI-compatible LLM
 LLM_BASE_URL=https://api.deepseek.com/chat/completions
 LLM_API_KEY=
diff --git a/README.md b/README.md
index 13a7449..bda8bfd 100644
--- a/README.md
+++ b/README.md
@@ -137,6 +137,34 @@ http://127.0.0.1:5173
 | `LLM_REASON_MODEL` | Reason 测试模型 |
 | `LLM_MOCK_ENABLED` | 是否强制 mock |
 | `LLM_FALLBACK_TO_MOCK` | 真实模型失败时是否回退 mock |
+| `AUTH_VALIDATE_ENABLED` | 是否启用 Django 用户中心鉴权 |
+| `AUTH_USER_ME_URL` | Django 当前用户接口，例如 `http://192.168.2.76:8000/api/user/users/me/` |
+| `AUTH_TIMEOUT_SECONDS` | 调用用户中心超时时间 |
+| `AUTH_CACHE_TTL_SECONDS` | 用户信息短期缓存时间 |
+| `AUTH_ALLOW_DEMO_USER_ID` | 外部鉴权开启时是否允许 `X-User-Id` Demo 兜底 |
+
+## Django 用户中心联调
+
+正式联调时，前端进入医疗问诊 Agent 后先调用：
+
+```text
+GET /api/v1/auth/me
+```
+
+前端需要携带宿主系统登录态：
+
+```http
+Authorization: Bearer <token>
+X-Entry-Scene: mac_vue_dev
+```
+
+如果宿主系统使用 Cookie 登录，则前端需要开启 `withCredentials`，后端会把 Cookie 转发到：
+
+```text
+http://192.168.2.76:8000/api/user/users/me/
+```
+
+FastAPI 会从 Django 返回值中提取 `user_id`，后续病例训练、会话、评价和历史记录都按该 `user_id` 隔离。`X-User-Id` 只作为本地 Demo 兼容方式。
 
 ## 验证命令
 
diff --git a/backend/app/api/auth.py b/backend/app/api/auth.py
new file mode 100644
index 0000000..4a33c23
--- /dev/null
+++ b/backend/app/api/auth.py
@@ -0,0 +1,22 @@
+from fastapi import APIRouter, Depends
+
+from app.core.response import ApiResponse, ok
+from app.core.user_context import UserContext, get_user_context
+from app.schemas.auth import AuthMeResponse
+
+router = APIRouter()
+
+
+@router.get("/me", response_model=ApiResponse[AuthMeResponse])
+async def auth_me(ctx: UserContext = Depends(get_user_context)):
+    """当前用户：返回经 Django 用户中心或 Demo Header 标准化后的用户信息。"""
+    return ok(
+        AuthMeResponse(
+            user_id=ctx.user_id,
+            source=ctx.auth_source,
+            username=ctx.username,
+            display_name=ctx.display_name,
+            tenant_id=ctx.tenant_id,
+            role=ctx.role,
+        )
+    )
diff --git a/backend/app/api/router.py b/backend/app/api/router.py
index 0226225..9059984 100644
--- a/backend/app/api/router.py
+++ b/backend/app/api/router.py
@@ -1,9 +1,10 @@
 from fastapi import APIRouter
 
-from app.api import agent, cases, evaluations, imports, knowledge, llm_test, sessions
+from app.api import agent, auth, cases, evaluations, imports, knowledge, llm_test, sessions
 
 api_router = APIRouter()
 api_router.include_router(agent.router, tags=["agent"])
+api_router.include_router(auth.router, prefix="/auth", tags=["auth"])
 api_router.include_router(cases.router, prefix="/cases", tags=["cases"])
 api_router.include_router(sessions.router, prefix="/sessions", tags=["sessions"])
 api_router.include_router(evaluations.router, prefix="/evaluations", tags=["evaluations"])
diff --git a/backend/app/core/config.py b/backend/app/core/config.py
index eff2c17..abcf5e6 100644
--- a/backend/app/core/config.py
+++ b/backend/app/core/config.py
@@ -83,6 +83,11 @@ class Settings(BaseModel):
     runtime_memory_ttl_seconds: int = Field(default_factory=lambda: int(os.getenv("RUNTIME_MEMORY_TTL_SECONDS", "7200")))
     runtime_memory_backend: str = Field(default_factory=lambda: os.getenv("RUNTIME_MEMORY_BACKEND", "memory"))
     redis_url: str = Field(default_factory=lambda: os.getenv("REDIS_URL", "redis://127.0.0.1:6379/0"))
+    auth_validate_enabled: bool = Field(default_factory=lambda: os.getenv("AUTH_VALIDATE_ENABLED", "false").lower() == "true")
+    auth_user_me_url: str = Field(default_factory=lambda: os.getenv("AUTH_USER_ME_URL", ""))
+    auth_timeout_seconds: int = Field(default_factory=lambda: int(os.getenv("AUTH_TIMEOUT_SECONDS", "5")))
+    auth_cache_ttl_seconds: int = Field(default_factory=lambda: int(os.getenv("AUTH_CACHE_TTL_SECONDS", "300")))
+    auth_allow_demo_user_id: bool = Field(default_factory=lambda: os.getenv("AUTH_ALLOW_DEMO_USER_ID", "true").lower() == "true")
 
     def as_public_dict(self) -> dict[str, Any]:
         """配置展示：返回允许暴露给 Demo 前端的功能开关。"""
@@ -102,6 +107,8 @@ class Settings(BaseModel):
             "llm_reasoning_effort": self.llm_reasoning_effort,
             "llm_fast_max_tokens": self.llm_fast_max_tokens,
             "runtime_memory_backend": self.runtime_memory_backend,
+            "auth_validate_enabled": self.auth_validate_enabled,
+            "auth_source": "django_user_center" if self.auth_validate_enabled else "demo_header",
         }
 
 
diff --git a/backend/app/core/context.py b/backend/app/core/context.py
index 7243267..912df82 100644
--- a/backend/app/core/context.py
+++ b/backend/app/core/context.py
@@ -13,3 +13,6 @@ class UserContext:
     request_id: str | None = None
     ip_address: str | None = None
     user_agent: str | None = None
+    username: str | None = None
+    display_name: str | None = None
+    auth_source: str = "demo_header"
diff --git a/backend/app/core/user_context.py b/backend/app/core/user_context.py
index 238ac73..6c1ee50 100644
--- a/backend/app/core/user_context.py
+++ b/backend/app/core/user_context.py
@@ -1,7 +1,9 @@
 from fastapi import Header, Request
 
+from app.core.config import settings
 from app.core.context import UserContext
 from app.core.exceptions import AppError
+from app.services.external_auth_service import ExternalAuthService
 
 
 async def get_user_context(
@@ -13,7 +15,26 @@ async def get_user_context(
     x_entry_scene: str | None = Header(default=None, alias="X-Entry-Scene"),
     x_request_id: str | None = Header(default=None, alias="X-Request-Id"),
 ) -> UserContext:
-    """用户校验：读取请求头并强制校验 `X-User-Id`。"""
+    """用户校验：正式联调优先调用 Django 用户中心，Demo 模式兼容 X-User-Id。"""
+    if settings.auth_validate_enabled and (request.headers.get("Authorization") or request.headers.get("Cookie")):
+        user = await ExternalAuthService().authenticate(request)
+        return UserContext(
+            user_id=user.user_id,
+            tenant_id=user.tenant_id or x_tenant_id,
+            role=user.role or x_user_role,
+            class_id=x_class_id,
+            entry_scene=x_entry_scene,
+            request_id=x_request_id,
+            ip_address=request.client.host if request.client else None,
+            user_agent=request.headers.get("User-Agent"),
+            username=user.username,
+            display_name=user.display_name,
+            auth_source=user.source,
+        )
+
+    if settings.auth_validate_enabled and not settings.auth_allow_demo_user_id:
+        raise AppError("AUTH_CREDENTIAL_REQUIRED", "Authorization or Cookie is required", 401)
+
     if not x_user_id or not x_user_id.strip():
         raise AppError("USER_ID_REQUIRED", "X-User-Id header is required", 401)
 
@@ -26,4 +47,5 @@ async def get_user_context(
         request_id=x_request_id,
         ip_address=request.client.host if request.client else None,
         user_agent=request.headers.get("User-Agent"),
+        auth_source="demo_header",
     )
diff --git a/backend/app/main.py b/backend/app/main.py
index 0188f04..43995e2 100644
--- a/backend/app/main.py
+++ b/backend/app/main.py
@@ -24,8 +24,8 @@ def create_app() -> FastAPI:
             "http://127.0.0.1:5174",
             "http://localhost:5174",
         ],
-        allow_origin_regex=r"^http://(127\.0\.0\.1|localhost):\d+$",
-        allow_credentials=False,
+        allow_origin_regex=r"^http://(127\.0\.0\.1|localhost|192\.168\.\d+\.\d+):\d+$",
+        allow_credentials=True,
         allow_methods=["*"],
         allow_headers=["*"],
     )
diff --git a/backend/app/schemas/auth.py b/backend/app/schemas/auth.py
new file mode 100644
index 0000000..ebccf45
--- /dev/null
+++ b/backend/app/schemas/auth.py
@@ -0,0 +1,12 @@
+from pydantic import BaseModel
+
+
+class AuthMeResponse(BaseModel):
+    """认证用户响应：返回医疗问诊 Agent 标准化后的当前用户信息。"""
+
+    user_id: str
+    source: str
+    username: str | None = None
+    display_name: str | None = None
+    tenant_id: str | None = None
+    role: str | None = None
diff --git a/backend/app/services/external_auth_service.py b/backend/app/services/external_auth_service.py
new file mode 100644
index 0000000..83a4000
--- /dev/null
+++ b/backend/app/services/external_auth_service.py
@@ -0,0 +1,128 @@
+from __future__ import annotations
+
+import hashlib
+import time
+from dataclasses import dataclass
+from typing import Any
+
+import httpx
+from fastapi import Request
+
+from app.core.config import settings
+from app.core.exceptions import AppError
+
+
+@dataclass(frozen=True)
+class AuthenticatedUser:
+    """外部认证用户：承载从 Django 用户中心解析出的标准用户信息。"""
+
+    user_id: str
+    source: str = "django_user_center"
+    username: str | None = None
+    display_name: str | None = None
+    tenant_id: str | None = None
+    role: str | None = None
+
+
+class ExternalAuthService:
+    """外部认证服务：调用 Django `/api/user/users/me/` 并标准化当前登录用户。"""
+
+    _cache: dict[str, tuple[float, AuthenticatedUser]] = {}
+
+    async def authenticate(self, request: Request) -> AuthenticatedUser:
+        """用户鉴权：转发前端鉴权凭证到 Django 用户中心，成功后返回标准用户信息。"""
+        if not settings.auth_user_me_url:
+            raise AppError("AUTH_CONFIG_MISSING", "auth user me url is not configured", 500)
+
+        outbound_headers = self._build_forward_headers(request)
+        if not outbound_headers:
+            raise AppError("AUTH_CREDENTIAL_REQUIRED", "Authorization or Cookie is required", 401)
+
+        cache_key = self._cache_key(outbound_headers)
+        cached = self._read_cache(cache_key)
+        if cached:
+            return cached
+
+        try:
+            async with httpx.AsyncClient(timeout=settings.auth_timeout_seconds, follow_redirects=False) as client:
+                response = await client.get(settings.auth_user_me_url, headers=outbound_headers)
+        except httpx.TimeoutException as exc:
+            raise AppError("AUTH_USER_CENTER_UNAVAILABLE", "auth user center request timeout", 503) from exc
+        except httpx.HTTPError as exc:
+            raise AppError("AUTH_USER_CENTER_UNAVAILABLE", "auth user center unavailable", 503) from exc
+
+        if response.status_code != 200:
+            raise AppError("AUTH_USER_INVALID", "current login user is invalid", 401)
+
+        try:
+            payload = response.json()
+        except ValueError as exc:
+            raise AppError("AUTH_USER_PARSE_FAILED", "auth user center returned invalid json", 502) from exc
+
+        user = self._parse_user(payload)
+        self._write_cache(cache_key, user)
+        return user
+
+    def _build_forward_headers(self, request: Request) -> dict[str, str]:
+        """认证转发：只透传鉴权必要 Header，避免把无关内部头转发给用户中心。"""
+        headers: dict[str, str] = {}
+        authorization = request.headers.get("Authorization")
+        cookie = request.headers.get("Cookie")
+        if authorization:
+            headers["Authorization"] = authorization
+        if cookie:
+            headers["Cookie"] = cookie
+        if request.headers.get("X-CSRFToken"):
+            headers["X-CSRFToken"] = request.headers["X-CSRFToken"]
+        return headers
+
+    def _parse_user(self, payload: dict[str, Any]) -> AuthenticatedUser:
+        """用户解析：兼容常见 Django 用户接口结构，并提取稳定 user_id。"""
+        data = payload.get("data") if isinstance(payload.get("data"), dict) else payload
+        user_id = self._first_present(data, ["id", "user_id", "uid", "pk", "uuid"])
+        if user_id is None:
+            raise AppError("AUTH_USER_PARSE_FAILED", "auth user id is missing", 502)
+        username = self._first_present(data, ["username", "account", "mobile", "phone"])
+        display_name = self._first_present(data, ["display_name", "name", "nickname", "real_name"])
+        role = self._first_present(data, ["role", "user_role"])
+        tenant_id = self._first_present(data, ["tenant_id", "org_id", "organization_id"])
+        return AuthenticatedUser(
+            user_id=str(user_id),
+            username=str(username) if username is not None else None,
+            display_name=str(display_name) if display_name is not None else None,
+            role=str(role) if role is not None else None,
+            tenant_id=str(tenant_id) if tenant_id is not None else None,
+        )
+
+    @staticmethod
+    def _first_present(data: dict[str, Any], keys: list[str]) -> Any:
+        """用户解析：按优先级读取第一个非空字段。"""
+        for key in keys:
+            value = data.get(key)
+            if value is not None and value != "":
+                return value
+        return None
+
+    @staticmethod
+    def _cache_key(headers: dict[str, str]) -> str:
+        """认证缓存：基于鉴权凭证生成不可逆缓存键，避免保存明文 token。"""
+        raw = "|".join(f"{key}:{value}" for key, value in sorted(headers.items()))
+        return hashlib.sha256(raw.encode("utf-8")).hexdigest()
+
+    def _read_cache(self, cache_key: str) -> AuthenticatedUser | None:
+        """认证缓存：读取进程内短期用户缓存，减少频繁请求 Django 用户中心。"""
+        item = self._cache.get(cache_key)
+        if not item:
+            return None
+        expires_at, user = item
+        if expires_at <= time.time():
+            self._cache.pop(cache_key, None)
+            return None
+        return user
+
+    def _write_cache(self, cache_key: str, user: AuthenticatedUser) -> None:
+        """认证缓存：写入短期用户缓存，缓存只保存标准用户信息，不保存 token 明文。"""
+        ttl = max(settings.auth_cache_ttl_seconds, 0)
+        if ttl <= 0:
+            return
+        self._cache[cache_key] = (time.time() + ttl, user)
diff --git a/backend/tests/test_api_contract.py b/backend/tests/test_api_contract.py
index 510cf57..2877b34 100644
--- a/backend/tests/test_api_contract.py
+++ b/backend/tests/test_api_contract.py
@@ -40,6 +40,11 @@ def run_api_contract_tests() -> None:
     assert hello.status_code == 200
     assert hello.json()["code"] == "OK"
 
+    auth_me = client.get("/api/v1/auth/me", headers=headers)
+    assert auth_me.status_code == 200
+    assert auth_me.json()["data"]["user_id"] == "api_user_001"
+    assert auth_me.json()["data"]["source"] == "demo_header"
+
     cases = client.get("/api/v1/cases", headers=headers)
     assert cases.status_code == 200
     case_id = cases.json()["data"]["items"][0]["id"]
diff --git a/docs/03_api_design.md b/docs/03_api_design.md
index fbfc4da..7bac01e 100644
--- a/docs/03_api_design.md
+++ b/docs/03_api_design.md
@@ -21,11 +21,18 @@ API base: http://127.0.0.1:8000/api/v1
 
 ### 1.2 必传 Header
 
-所有业务接口都必须携带以下 Header：
+正式联调时，前端必须携带宿主系统登录态，推荐使用 `Authorization`：
 
 | Header | 类型 | 说明 |
 |---|---:|---|
-| `X-User-Id` | string | 宿主系统传入的用户标识。后端按该字段隔离会话、提交、评价和历史记录。 |
+| `Authorization` | string | 宿主系统登录 token，例如 `Bearer <token>`。医疗问诊 Agent 会转发到 Django `/api/user/users/me/`。 |
+| `Cookie` | string | 如果宿主系统使用 Cookie 登录，浏览器可通过 `withCredentials` 携带 Cookie。 |
+
+本地 Demo 兼容以下 Header：
+
+| Header | 类型 | 说明 |
+|---|---:|---|
+| `X-User-Id` | string | Demo 兼容用户标识。正式联调启用外部鉴权后，以 Django `/me/` 返回的用户为准。 |
 | `X-Entry-Scene` | string | 入口场景。Demo 前端默认 `vue_demo`。 |
 
 可选 Header：
@@ -78,11 +85,16 @@ API base: http://127.0.0.1:8000/api/v1
 | `CASE_SQL_FILE_EMPTY` | SQL 文件为空 | 提示重新导出文件。 |
 | `CASE_SQL_FILE_TOO_LARGE` | 文件超过 5MB | 提示压缩或拆分。 |
 | `CASE_SQL_IMPORT_INVALID` | SQL 解析或字段映射失败 | 展示 `errors`，不允许确认导入。 |
+| `AUTH_CREDENTIAL_REQUIRED` | 启用外部鉴权后未携带 Authorization/Cookie | 引导用户回宿主系统登录。 |
+| `AUTH_USER_CENTER_UNAVAILABLE` | Django 用户中心不可访问或超时 | 提示稍后重试，检查用户中心服务。 |
+| `AUTH_USER_INVALID` | Django 返回用户无效或登录态过期 | 引导用户重新登录。 |
+| `AUTH_USER_PARSE_FAILED` | Django 返回结构无法提取 user_id | 联系后端确认用户接口字段。 |
 
 ## 2. 前端主流程
 
 ```text
 入口页
+  -> GET /auth/me
   -> GET /agent/hello
 病例页
   -> GET /cases
@@ -130,7 +142,73 @@ inquiry -> diagnosis -> treatment -> evaluating -> evaluated
 | `evaluating` | 生成评价报告 |
 | `evaluated` | 查看报告、导出 PDF、查看历史 |
 
-## 3. Agent Hello
+## 3. 认证接口
+
+### `GET /auth/me`
+
+用途：进入医疗问诊 Agent 前校验当前登录用户，并返回标准化用户信息。
+
+调用链路：
+
+```text
+Vue 前端
+  -> GET /api/v1/auth/me
+FastAPI 医疗问诊 Agent
+  -> GET http://192.168.2.76:8000/api/user/users/me/
+Django 用户中心
+  -> 返回当前登录用户
+FastAPI
+  -> 提取 user_id 并返回标准结构
+```
+
+正式联调请求头：
+
+```http
+Authorization: Bearer <宿主系统token>
+X-Entry-Scene: mac_vue_dev
+```
+
+Cookie 登录时：
+
+```http
+Cookie: sessionid=...
+X-Entry-Scene: mac_vue_dev
+```
+
+Response `data`：
+
+```json
+{
+  "user_id": "123",
+  "source": "django_user_center",
+  "username": "zhangsan",
+  "display_name": "张三",
+  "tenant_id": null,
+  "role": null
+}
+```
+
+本地 Demo 兼容模式中，如果未开启外部鉴权或允许 `X-User-Id` 兜底，返回：
+
+```json
+{
+  "user_id": "demo_user_001",
+  "source": "demo_header",
+  "username": null,
+  "display_name": null,
+  "tenant_id": null,
+  "role": null
+}
+```
+
+前端处理规则：
+
+- 进入 Agent 时先调用 `/auth/me`。
+- 成功后使用返回的 `user_id` 展示当前用户。
+- 后续业务接口继续携带相同 `Authorization` 或 Cookie。
+- 正式联调不要让用户手动输入 `X-User-Id`。
+
+## 4. Agent Hello
 
 ### `GET /agent/hello`
 
@@ -170,7 +248,7 @@ Response `data`：
 - `llm_fallback_to_mock`：真实模型失败时是否回退 mock。
 - `runtime_memory_backend`：短期记忆后端，通常为 `redis` 或 `memory`。
 
-## 4. 病例接口
+## 5. 病例接口
 
 ### `GET /cases`
 
@@ -301,7 +379,7 @@ Response `data`：
 - 用户输入固定确认文案后再调用 `DELETE`。
 - 删除成功后清空当前病例、会话、检查结果、报告缓存，并刷新 `/cases`。
 
-## 5. 会话与问诊接口
+## 6. 会话与问诊接口
 
 ### `POST /sessions`
 
@@ -436,7 +514,7 @@ Response `data`：
 - 练习模式中是否点击提示不影响评分链路。
 - 教学互动模式当前不显示提示入口。
 
-## 6. 检查/检验接口
+## 7. 检查/检验接口
 
 ### `GET /sessions/{session_id}/order-items`
 
@@ -491,7 +569,7 @@ Response `data`：
 - 重复申请不重复写入 runtime memory。
 - 前端按 `item_code` 去重展示。
 
-## 7. 阶段提交接口
+## 8. 阶段提交接口
 
 ### `POST /sessions/{session_id}/complete-inquiry`
 
@@ -554,7 +632,7 @@ Response `data`：
 }
 ```
 
-## 8. 评价与报告接口
+## 9. 评价与报告接口
 
 ### `POST /sessions/{session_id}/evaluation`
 
@@ -650,7 +728,7 @@ Response `data`：
 }
 ```
 
-## 9. 病例 SQL 导入接口
+## 10. 病例 SQL 导入接口
 
 ### `POST /imports/case-sql/preview`
 
@@ -726,7 +804,7 @@ Response `data`：
 - 导入成功后刷新病例列表。
 - 如果源 SQL 缺少 `case_exam_item`，后端会生成基础检查项，保证新病例可训练。
 
-## 10. 知识检索接口
+## 11. 知识检索接口
 
 ### `GET /knowledge/search`
 
@@ -750,7 +828,7 @@ Response `data`：
 }
 ```
 
-## 11. LLM 测试接口
+## 12. LLM 测试接口
 
 ### `POST /llm/test/deepseek-fast`
 
@@ -787,7 +865,7 @@ Request 同 Fast 测试。
 
 Response 字段同 Fast 测试。
 
-## 12. 前端字段枚举
+## 13. 前端字段枚举
 
 | 字段 | 允许值 |
 |---|---|
@@ -797,7 +875,7 @@ Response 字段同 Fast 测试。
 | `session.status` | `inquiry`、`diagnosis`、`treatment`、`evaluating`、`evaluated` |
 | `patient.gender` | `male`、`female`、`null` |
 
-## 13. 前端联调注意事项
+## 14. 前端联调注意事项
 
 1. 所有请求必须带 `X-User-Id`，否则后端返回 `USER_ID_REQUIRED`。
 2. 当前 Demo 不做登录注册，`user_id` 由宿主系统或测试页传入。