diff --git a/gate.lua b/gate.lua
index 705d8c7..78ed927 100644
--- a/gate.lua
+++ b/gate.lua
@@ -100,8 +100,12 @@ end
 
 
 local function checkAndApplyUpdate()
-  if type(CFG) ~= 'table' then return end
-  local remoteTs = tonumber(CFG.update_counter)
+  local serverBase = guessBaseFromStatusURL(serverURL)
+  if #serverBase == 0 then return end
+  local url = serverBase:gsub("/+$", "") .. "/api/check-update?_t=" .. tostring(nowMs() + math.random(1, 999999))
+  local ok, data = getJSON(url)
+  if not ok or not data or not data.update_counter then return end
+  local remoteTs = tonumber(data.update_counter)
   
   if not remoteTs or remoteTs <= 0 then return end
   
diff --git a/server/routes/api.js b/server/routes/api.js
index 672ab50..01389fb 100644
--- a/server/routes/api.js
+++ b/server/routes/api.js
@@ -151,6 +151,18 @@ const resolveCurrentStationCode = (body, resolveStation) => {
   return codes[0] || direct || fallback || '';
 };
 
+// Dedicated lightweight OTA update endpoints
+let globalUpdateCounter = Date.now();
+
+router.post('/trigger-update', (req, res) => {
+  globalUpdateCounter++;
+  res.json({ ok: true, update_counter: globalUpdateCounter });
+});
+
+router.get('/check-update', (req, res) => {
+  res.json({ update_counter: globalUpdateCounter });
+});
+
 // Config
 router.get('/config', (req, res) => {
   const cfg = DataService.getConfig();
@@ -190,9 +202,7 @@ router.put('/config', async (req, res) => {
     if (typeof incoming.force_update === 'boolean') {
       cfg.force_update = incoming.force_update;
     }
-    if (incoming.update_counter) {
-      cfg.update_counter = incoming.update_counter;
-    }
+// remove unused update_counter
     await DataService.saveConfig(cfg);
     appendReqLog(req, { category: 'admin', type: 'update_config_generic', detail: incoming });
     io.emit('config:updated', cfg);
diff --git a/ticketmachine.lua b/ticketmachine.lua
index 7ef649f..02d3d5a 100644
--- a/ticketmachine.lua
+++ b/ticketmachine.lua
@@ -690,8 +690,11 @@ local function drawVersionIndicator()
 end
 
 local function checkAndApplyUpdate()
-  if type(CFG) ~= 'table' then return end
-  local remoteTs = tonumber(CFG.update_counter)
+  local txt = fetchHTTP(API_BASE .. '/check-update?_t=' .. tostring(os.epoch and os.epoch("utc") or math.random(1, 999999)))
+  if not txt then return end
+  local data = jsonDecode(txt)
+  if not data or not data.update_counter then return end
+  local remoteTs = tonumber(data.update_counter)
   
   if not remoteTs or remoteTs <= 0 then return end
   
diff --git a/web/index.js b/web/index.js
index ecb7500..700efad 100644
--- a/web/index.js
+++ b/web/index.js
@@ -1483,12 +1483,9 @@ createApp({
             
             isPushingUpdate.value = true;
             
-            // 每次点击，更新计数器 +1，终端只要看到计数器变大就会更新
-            config.update_counter = (config.update_counter || 0) + 1;
-            config.force_update = true;
-            
             try {
-                await requestJson('/api/config', { method: 'PUT', headers: {'Content-Type': 'application/json'}, body: JSON.stringify(config) }, { expectOk: true });
+                // 直接请求专门的轻量级触发更新接口，避免和庞大的配置文件保存混在一起导致超时
+                await requestJson('/api/trigger-update', { method: 'POST' }, { expectOk: true });
                 alert('推送指令发送完毕，终端将陆续更新');
             } catch (err) {
                 console.error(err);