diff --git a/backend/server.js b/backend/server.js
index 5296440..d46e1da 100644
--- a/backend/server.js
+++ b/backend/server.js
@@ -1,3 +1,6 @@
+// 加载环境变量（必须在最开始）
+require('dotenv').config();
+
 const express = require('express');
 const cors = require('cors');
 const cookieParser = require('cookie-parser');