diff --git a/app/api/join/route.ts b/app/api/join/route.ts
index 0f696fe..2541393 100644
--- a/app/api/join/route.ts
+++ b/app/api/join/route.ts
@@ -133,6 +133,28 @@ async function tryPocketBaseDirect(
 
   const pb = getPocketBaseConfig();
   const base = pb.url.replace(/\/$/, "");
+  const wechatId = String(record.wechatId ?? "").trim();
+  if (wechatId) {
+    const escaped = wechatId.replace(/\\/g, "\\\\").replace(/"/g, '\\"');
+    const filter = encodeURIComponent(`wechatId = "${escaped}"`);
+    const checkRes = await fetch(
+      `${base}/api/collections/${pb.joinCollection}/records?filter=${filter}&perPage=1`,
+      {
+        headers: { Authorization: `Bearer ${token}` },
+        cache: "no-store",
+      }
+    );
+    if (checkRes.ok) {
+      const checkData = await checkRes.json();
+      if (Array.isArray((checkData as { items?: unknown[] }).items) && (checkData as { items: unknown[] }).items.length > 0) {
+        return NextResponse.json(
+          { ok: false, error: "该微信号已报名，请勿重复提交" },
+          { status: 400 }
+        );
+      }
+    }
+  }
+
   const url = `${base}/api/collections/${pb.joinCollection}/records`;
 
   const qualify = !!(record.qualify ?? false);
diff --git a/app/join/page.tsx b/app/join/page.tsx
index 24133d8..e88dfaa 100644
--- a/app/join/page.tsx
+++ b/app/join/page.tsx
@@ -142,7 +142,8 @@ export default function JoinPage() {
   const [paying, setPaying] = useState(false);
   const initialWechatCheckDone = useRef(false);
   const lastSubmitTime = useRef(0);
-  const SUBMIT_THROTTLE_MS = 2000;
+  const submittingRef = useRef(false);
+  const SUBMIT_THROTTLE_MS = 3000;
 
   const fetchByWechat = async (w: string) => {
     if (!w.trim()) return;
@@ -247,24 +248,12 @@ export default function JoinPage() {
     setError(null);
 
     const now = Date.now();
-    if (now - lastSubmitTime.current < SUBMIT_THROTTLE_MS) {
-      return;
-    }
+    if (submittingRef.current) return;
+    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=${encodeURIComponent(wechat.trim())}`, { cache: "no-store" });
-      const checkData = await checkRes.json();
-      if (checkData?.hasRecord) {
-        setError("该微信号已报名，请勿重复提交");
-        fetchByWechat(wechat.trim());
-        return;
-      }
-    } catch {
-      /* 校验失败时继续提交，由后端兜底 */
-    }
     if (xiaohongshuUrl.trim() && urlError) {
       setError("请先修正小红书链接");
       return;
@@ -285,9 +274,22 @@ export default function JoinPage() {
       setError("请选择性别");
       return;
     }
+
+    submittingRef.current = true;
     lastSubmitTime.current = now;
     setSubmitting(true);
+
     try {
+      const checkRes = await fetch(`/api/join/by-wechat?wechat_id=${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());
+        submittingRef.current = false;
+        setSubmitting(false);
+        return;
+      }
+
       const formGenderFemale = gender === "女" || gender === "female";
       const postCountOk = (profile?.postCount ?? 0) > 10;
       const qualify = formGenderFemale && postCountOk;
@@ -318,7 +320,7 @@ export default function JoinPage() {
           why_join: "",
           region: "",
           available_time: "",
-          qualify, // 女性且小红书帖子>10 时自动通过审核
+          qualify,
           is_volunteer: fromVolunteer,
         }),
       });
@@ -328,11 +330,19 @@ export default function JoinPage() {
       }
       setQualify(qualify);
       setSubmitted(true);
-      // 提交成功后立即按微信号查询，用真实记录状态展示（审核中/审核通过等），避免刷新后状态不一致
-      fetchByWechat(wechat.trim());
+      try {
+        await fetchByWechat(wechat.trim());
+      } catch {
+        try {
+          localStorage.setItem(WECHAT_STORAGE_KEY, wechat.trim());
+        } catch {}
+        window.location.replace("/join");
+        return;
+      }
     } catch (err) {
       setError(err instanceof Error ? err.message : "网络错误，请重试");
     } finally {
+      submittingRef.current = false;
       setSubmitting(false);
     }
   };