diff --git a/ft-app/app/collector.py b/ft-app/app/collector.py
index 05f320f..17f73b0 100644
--- a/ft-app/app/collector.py
+++ b/ft-app/app/collector.py
@@ -1,13 +1,16 @@
 """Data collector — fetch OHLCV from akshare and upsert into daily_bars."""
 import threading
+import time
 from datetime import date
 from app.database import SessionLocal
 from app.models import DailyBar, Contract
 from app.engine.lock_strategy import compute_amp_5d
 
-_progress = {"running": False, "label": "", "done": 0, "total": 0, "result": 0, "finished": False, "error": ""}
+_progress = {"running": False, "label": "", "done": 0, "total": 0, "result": 0, "finished": False, "error": "", "started_at": 0}
 _lock = threading.Lock()
 
+STALE_SECONDS = 120
+
 
 def get_progress() -> dict:
     with _lock:
@@ -16,9 +19,10 @@ def get_progress() -> dict:
 
 def _start_bg(target, label):
     with _lock:
-        if _progress["running"]:
+        now = time.time()
+        if _progress["running"] and (now - _progress["started_at"]) < STALE_SECONDS:
             return False
-        _progress.update(running=True, finished=False, label=label, done=0, total=0, error="")
+        _progress.update(running=True, finished=False, label=label, done=0, total=0, error="", started_at=now)
 
     def _run():
         try:
diff --git a/ft-app/app/templates/admin.html b/ft-app/app/templates/admin.html
index b5700ed..7c2aa0f 100644
--- a/ft-app/app/templates/admin.html
+++ b/ft-app/app/templates/admin.html
@@ -265,7 +265,14 @@ function startSync(url) {
   fetch(url, { method: 'POST' })
     .then(function(r) { return r.json(); })
     .then(function(data) {
-      if (!data.ok) { hideProgress(); return; }
+      if (!data.ok) {
+        document.getElementById('sync-progress-label').textContent = '已有同步任务进行中，请稍后再试';
+        document.getElementById('sync-progress-pct').textContent = '';
+        document.getElementById('sync-progress-bar').style.width = '0%';
+        document.getElementById('sync-progress').insertAdjacentHTML('beforeend',
+          '<button onclick="hideProgress()" style="display:block;margin-top:10px;padding:4px 14px;border:1px solid var(--border);border-radius:5px;background:var(--surface);color:var(--fg);cursor:pointer;font-size:0.8rem;">关闭</button>');
+        return;
+      }
       syncTimer = setInterval(pollProgress, 500);
     });
 }