diff --git a/README.md b/README.md
index 5e8cb8e..5d389c4 100644
--- a/README.md
+++ b/README.md
@@ -71,7 +71,8 @@ cd ..
 访问地址：
 
 ```text
-http://localhost:9081
+新版前端：http://localhost:9081
+旧版前端：http://localhost:9082
 ```
 
 开发前端时可运行：
diff --git a/app/main.py b/app/main.py
index ad4397d..5de7a6d 100644
--- a/app/main.py
+++ b/app/main.py
@@ -1,10 +1,11 @@
 from pathlib import Path
+import socket
+from typing import Literal
 
 import uvicorn
 from fastapi import FastAPI, HTTPException, Request
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import FileResponse, JSONResponse
-from fastapi.staticfiles import StaticFiles
 
 from app import state
 from app.api.routers import auth, cache, config, database, health, history, script, service, tasks, upload
@@ -13,12 +14,15 @@ from app.config import BASE_DIR
 
 
 APP_VERSION = "2.0.2"
+APP_HOST = "0.0.0.0"
+NEW_FRONTEND_PORT = 9081
+OLD_FRONTEND_PORT = 9082
 FRONTEND_DIST_DIR = BASE_DIR / "frontend" / "dist"
-FRONTEND_ASSETS_DIR = FRONTEND_DIST_DIR / "assets"
 FRONTEND_OLD_DIR = BASE_DIR / "frontend_old"
+FrontendMode = Literal["new", "old", "split"]
 
 
-def create_app() -> FastAPI:
+def create_app(frontend_mode: FrontendMode = "new") -> FastAPI:
     app = FastAPI(
         title="CapacityReport",
         description="容量报表数据处理系统",
@@ -38,7 +42,7 @@ def create_app() -> FastAPI:
 
     app.middleware("http")(jwt_middleware)
     register_routes(app)
-    register_frontend(app)
+    register_frontend(app, frontend_mode)
     return app
 
 
@@ -73,61 +77,130 @@ def register_routes(app: FastAPI) -> None:
         app.include_router(router)
 
 
-def register_frontend(app: FastAPI) -> None:
+def register_frontend(app: FastAPI, frontend_mode: FrontendMode) -> None:
     @app.get("/old", include_in_schema=False)
-    async def serve_old_frontend():
-        index_file = FRONTEND_OLD_DIR / "index.html"
-        if index_file.exists():
-            return FileResponse(str(index_file))
-        return JSONResponse(status_code=503, content={"detail": "旧版前端入口文件不存在"})
+    async def serve_old_frontend(request: Request):
+        if not _should_serve_old_frontend(request, frontend_mode):
+            raise HTTPException(status_code=404, detail=f"旧版前端请访问 {OLD_FRONTEND_PORT} 端口")
+        return _serve_old_index()
 
-    if FRONTEND_OLD_DIR.exists():
-        app.mount("/old", StaticFiles(directory=str(FRONTEND_OLD_DIR), html=True), name="frontend_old")
-
-    if FRONTEND_ASSETS_DIR.exists():
-        app.mount("/assets", StaticFiles(directory=str(FRONTEND_ASSETS_DIR)), name="assets")
+    @app.get("/old/{path:path}", include_in_schema=False)
+    async def serve_old_frontend_file(request: Request, path: str):
+        if not _should_serve_old_frontend(request, frontend_mode):
+            raise HTTPException(status_code=404, detail=f"旧版前端请访问 {OLD_FRONTEND_PORT} 端口")
+        return _serve_old_file(path)
 
     @app.get("/", include_in_schema=False)
     @app.get("/{path:path}", include_in_schema=False)
-    async def serve_spa(path: str = ""):
+    async def serve_frontend(request: Request, path: str = ""):
         if path.startswith("api/"):
             raise HTTPException(status_code=404, detail="接口不存在")
 
-        if not FRONTEND_DIST_DIR.exists():
-            return JSONResponse(
-                status_code=503,
-                content={
-                    "detail": "前端构建产物不存在，请先执行 cd frontend && npm install && npm run build"
-                },
-            )
+        if _should_serve_old_frontend(request, frontend_mode):
+            return _serve_old_frontend_path(path)
 
-        requested_file = _safe_frontend_file(path)
-        if requested_file and requested_file.exists() and requested_file.is_file():
-            return FileResponse(str(requested_file))
-
-        index_file = FRONTEND_DIST_DIR / "index.html"
-        if index_file.exists():
-            return FileResponse(str(index_file))
-
-        return JSONResponse(status_code=503, content={"detail": "前端入口文件不存在"})
+        return _serve_new_frontend_path(path)
 
 
-def _safe_frontend_file(path: str) -> Path | None:
+def _should_serve_old_frontend(request: Request, frontend_mode: FrontendMode) -> bool:
+    if frontend_mode == "old":
+        return True
+    if frontend_mode == "new":
+        return False
+    return _request_port(request) == OLD_FRONTEND_PORT
+
+
+def _request_port(request: Request) -> int | None:
+    server = request.scope.get("server")
+    if isinstance(server, tuple) and len(server) >= 2:
+        return server[1]
+    return request.url.port
+
+
+def _serve_new_frontend_path(path: str):
+    if not FRONTEND_DIST_DIR.exists():
+        return JSONResponse(
+            status_code=503,
+            content={"detail": "前端构建产物不存在，请先执行 cd frontend && npm install && npm run build"},
+        )
+
+    requested_file = _safe_file(FRONTEND_DIST_DIR, path)
+    if requested_file and requested_file.exists() and requested_file.is_file():
+        return FileResponse(str(requested_file))
+
+    index_file = FRONTEND_DIST_DIR / "index.html"
+    if index_file.exists():
+        return FileResponse(str(index_file))
+
+    return JSONResponse(status_code=503, content={"detail": "前端入口文件不存在"})
+
+
+def _serve_old_frontend_path(path: str):
+    if not path:
+        return _serve_old_index()
+
+    requested_file = _safe_file(FRONTEND_OLD_DIR, path)
+    if requested_file and requested_file.exists() and requested_file.is_file():
+        return FileResponse(str(requested_file))
+
+    return _serve_old_index()
+
+
+def _serve_old_file(path: str):
+    requested_file = _safe_file(FRONTEND_OLD_DIR, path)
+    if requested_file and requested_file.exists() and requested_file.is_file():
+        return FileResponse(str(requested_file))
+    raise HTTPException(status_code=404, detail="旧版前端文件不存在")
+
+
+def _serve_old_index():
+    if not FRONTEND_OLD_DIR.exists():
+        return JSONResponse(status_code=503, content={"detail": "旧版前端目录不存在"})
+
+    index_file = FRONTEND_OLD_DIR / "index.html"
+    if index_file.exists():
+        return FileResponse(str(index_file))
+
+    return JSONResponse(status_code=503, content={"detail": "旧版前端入口文件不存在"})
+
+
+def _safe_file(root: Path, path: str) -> Path | None:
     if not path:
         return None
 
-    requested = (FRONTEND_DIST_DIR / path).resolve()
+    root = root.resolve()
+    requested = (root / path).resolve()
     try:
-        requested.relative_to(FRONTEND_DIST_DIR.resolve())
+        requested.relative_to(root)
     except ValueError:
         return None
     return requested
 
 
-app = create_app()
+def _create_listen_socket(port: int) -> socket.socket:
+    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    sock.bind((APP_HOST, port))
+    sock.listen(2048)
+    sock.set_inheritable(True)
+    return sock
+
+
+def run_split_frontend_servers() -> None:
+    sockets = [_create_listen_socket(NEW_FRONTEND_PORT), _create_listen_socket(OLD_FRONTEND_PORT)]
+    config = uvicorn.Config(split_app, host=APP_HOST, port=NEW_FRONTEND_PORT, reload=False)
+    server = uvicorn.Server(config)
+    server.run(sockets=sockets)
+
+
+app = create_app("new")
+old_app = create_app("old")
+split_app = create_app("split")
 
 
 if __name__ == "__main__":
     print(f"CapacityReport v{APP_VERSION}")
     print(f"配置更新时间: {state.config.update}")
-    uvicorn.run("app.main:app", host="0.0.0.0", port=9081, reload=False)
+    print(f"新版前端: http://localhost:{NEW_FRONTEND_PORT}")
+    print(f"旧版前端: http://localhost:{OLD_FRONTEND_PORT}")
+    run_split_frontend_servers()
diff --git a/build/Dockerfile b/build/Dockerfile
index 26612a8..bd98447 100644
--- a/build/Dockerfile
+++ b/build/Dockerfile
@@ -35,7 +35,7 @@ COPY --from=frontend-build /frontend/dist /app/frontend/dist
 
 RUN chmod +x /app/start.sh 2>/dev/null || true
 
-EXPOSE 9081
+EXPOSE 9081 9082
 
 HEALTHCHECK --interval=30s --timeout=10s --start-period=10s --retries=3 \
     CMD curl -f http://localhost:9081/health || exit 1
diff --git a/build/README.md b/build/README.md
index cba84e0..0322f89 100644
--- a/build/README.md
+++ b/build/README.md
@@ -55,4 +55,4 @@ sh update.sh
 - 默认镜像版本
 - 版本要求范围
 - 数据库账号密码
-- 端口映射
+- 端口映射：新版前端 `19081 -> 9081`，旧版前端 `19082 -> 9082`
diff --git a/build/build.py b/build/build.py
index d68cc70..fad5181 100644
--- a/build/build.py
+++ b/build/build.py
@@ -36,8 +36,12 @@ MYSQL_HOST = "capacity-mysql"
 MYSQL_PORT = 3306
 
 # 应用端口映射
-APP_PORT_HOST = 19081
-APP_PORT_CONTAINER = 9081
+APP_NEW_PORT_HOST = 19081
+APP_NEW_PORT_CONTAINER = 9081
+APP_OLD_PORT_HOST = 19082
+APP_OLD_PORT_CONTAINER = 9082
+APP_PORT_HOST = APP_NEW_PORT_HOST
+APP_PORT_CONTAINER = APP_NEW_PORT_CONTAINER
 MYSQL_PORT_HOST = 13306
 MYSQL_PORT_CONTAINER = 3306
 
@@ -294,7 +298,8 @@ check_port() {{
     fi
 {{}}
 
-check_port {APP_PORT_HOST} "App"
+check_port {APP_NEW_PORT_HOST} "New frontend"
+check_port {APP_OLD_PORT_HOST} "Old frontend"
 check_port {MYSQL_PORT_HOST} "MySQL"
 
 echo ""
@@ -441,7 +446,8 @@ echo "=========================================="
 echo "Deployment completed!"
 echo "=========================================="
 echo ""
-echo "Access: http://localhost:{APP_PORT_HOST}"
+echo "New frontend: http://localhost:{APP_NEW_PORT_HOST}"
+echo "Old frontend: http://localhost:{APP_OLD_PORT_HOST}"
 echo ""
 echo "Commands:"
 echo "  Logs:    $DOCKER_COMPOSE_CMD logs -f"
@@ -637,7 +643,8 @@ echo "=========================================="
 echo "Update completed!"
 echo "=========================================="
 echo ""
-echo "Application: http://localhost:{APP_PORT_HOST}"
+echo "New frontend: http://localhost:{APP_NEW_PORT_HOST}"
+echo "Old frontend: http://localhost:{APP_OLD_PORT_HOST}"
 echo ""
 echo "Database status:"
 if docker ps --format "{{.Names}}" | grep -q "capacity-mysql"; then
diff --git a/build/docker-compose.yml b/build/docker-compose.yml
index 3421433..7b5fb53 100644
--- a/build/docker-compose.yml
+++ b/build/docker-compose.yml
@@ -16,6 +16,7 @@ services:
     restart: unless-stopped
     ports:
       - "19081:9081"
+      - "19082:9082"
     volumes:
       # 持久化数据
       - ./cache:/app/cache
diff --git a/docs/project_context.md b/docs/project_context.md
index 415f7c7..adc0a06 100644
--- a/docs/project_context.md
+++ b/docs/project_context.md
@@ -1,5 +1,12 @@
 # 项目上下文记录
 
+## 2026-05-15：拆分新旧前端访问端口
+
+- `python -m app.main` 现在由同一个 FastAPI 进程同时监听 `9081` 和 `9082`，共享后端运行状态、任务锁和 API。
+- `9081` 固定服务新版 Vue 3 前端，`9082` 固定服务 `frontend_old/` 旧版 HTML/CSS/JS 前端；旧版页面仍通过 `/old/...` 加载本地 Monaco 等静态资源。
+- `app.main:app` 保留为新版单端口 ASGI 实例，`app.main:old_app` 保留为旧版单端口 ASGI 实例，`app.main:split_app` 用于按请求端口切换前端。
+- `run.bat`、`supervisord.conf`、Dockerfile、Docker Compose 和离线构建脚本已同步新旧端口：本地为 `9081/9082`，容器宿主机映射为 `19081/19082`。
+
 ## 2026-05-15：增加旧版前端对照入口和新版路由
 
 - 从旧提交 `54773f547f6fcb853d73785f05ff5ac39ab2e5f5` 恢复原生 HTML/CSS/JS 前端到 `frontend_old/`，包含旧版 `index.html`、`login.html`、样式、脚本和本地 Monaco 资源。
diff --git a/run.bat b/run.bat
index dc93646..7969486 100644
--- a/run.bat
+++ b/run.bat
@@ -40,7 +40,8 @@ if not exist "frontend\dist\index.html" (
 :loop
 echo.
 echo [%date% %time%] Starting service...
-echo [INFO] Service URL: http://localhost:9081
+echo [INFO] New frontend: http://localhost:9081
+echo [INFO] Old frontend: http://localhost:9082
 echo [INFO] Close this window to stop the service.
 echo.
 
diff --git a/supervisord.conf b/supervisord.conf
index 0921bab..40f9fea 100644
--- a/supervisord.conf
+++ b/supervisord.conf
@@ -16,7 +16,7 @@ supervisor.rpcinterface_factory = supervisor.rpcinterface:make_main_rpcinterface
 serverurl=unix:///var/run/supervisor.sock
 
 [program:fastapi]
-command=uvicorn app.main:app --host 0.0.0.0 --port 9081 --workers 1
+command=python -m app.main
 directory=/app
 autostart=true
 autorestart=true