diff --git a/app/join/page.tsx b/app/join/page.tsx
index 5e9cdb2..24133d8 100644
--- a/app/join/page.tsx
+++ b/app/join/page.tsx
@@ -141,6 +141,8 @@ export default function JoinPage() {
   const [fromVolunteer, setFromVolunteer] = useState(false);
   const [paying, setPaying] = useState(false);
   const initialWechatCheckDone = useRef(false);
+  const lastSubmitTime = useRef(0);
+  const SUBMIT_THROTTLE_MS = 2000;
 
   const fetchByWechat = async (w: string) => {
     if (!w.trim()) return;
@@ -243,6 +245,26 @@ export default function JoinPage() {
   const handleSubmit = async (e: FormEvent) => {
     e.preventDefault();
     setError(null);
+
+    const now = Date.now();
+    if (now - lastSubmitTime.current < SUBMIT_THROTTLE_MS) {
+      return;
+    }
+    if (userRecord?.hasRecord) {
+      setError("该微信号已报名，请勿重复提交");
+      return;
+    }
+    try {
+      const checkRes = await fetch(`/api/join/by-wechat?wechat_id=${encodeURIComponent(wechat.trim())}`, { cache: "no-store" });
+      const checkData = await checkRes.json();
+      if (checkData?.hasRecord) {
+        setError("该微信号已报名，请勿重复提交");
+        fetchByWechat(wechat.trim());
+        return;
+      }
+    } catch {
+      /* 校验失败时继续提交，由后端兜底 */
+    }
     if (xiaohongshuUrl.trim() && urlError) {
       setError("请先修正小红书链接");
       return;
@@ -263,6 +285,7 @@ export default function JoinPage() {
       setError("请选择性别");
       return;
     }
+    lastSubmitTime.current = now;
     setSubmitting(true);
     try {
       const formGenderFemale = gender === "女" || gender === "female";
diff --git a/next.config.ts b/next.config.ts
index 095ed6f..c20d725 100644
--- a/next.config.ts
+++ b/next.config.ts
@@ -2,6 +2,18 @@ import type { NextConfig } from "next";
 
 const nextConfig: NextConfig = {
   reactStrictMode: true,
+  async headers() {
+    return [
+      {
+        source: "/:path*",
+        headers: [
+          { key: "Cache-Control", value: "no-store, no-cache, must-revalidate, proxy-revalidate" },
+          { key: "Pragma", value: "no-cache" },
+          { key: "Expires", value: "0" },
+        ],
+      },
+    ];
+  },
   images: {
     remotePatterns: [
       { protocol: "https", hostname: "picsum.photos", pathname: "/**" },