diff --git a/includes/language/zh.json b/includes/language/zh.json
index ab828ea..6c51195 100644
--- a/includes/language/zh.json
+++ b/includes/language/zh.json
@@ -61,6 +61,8 @@
     "ERR0059": "timezone設定失敗",
     "ERR0060": "手環ID輸入錯誤",
     "ERR0061": "手環ID已存在",
+    "ERR0062": "機器序號輸入錯誤",
+    "ERR0063": "機器序號已存在",
 
     "ERR7000": "命令執行失敗",
 
diff --git a/route/api/wristband.js b/route/api/wristband.js
index 1e96a91..f64ed6b 100644
--- a/route/api/wristband.js
+++ b/route/api/wristband.js
@@ -311,6 +311,18 @@ router
     .post('/addlocation', (req, res, n) => {
         if (!config.permission.wristband) return n('ERR9000');
         if (!tool.checkPermission(req)) return n('ERR9000');
+        let arr = req.body;
+        if (!arr.data) return n('ERR0000');
+        if (!arr.data.sn) return n("ERR0062");
+        if (!arr.data.name) return n('ERR0026');
+
+        let query = "select count(*) as c from ??.?? where `serialnumber` = ?";
+        let param = [config.db.db9, 'location', arr.data.sn];
+
+        res.db.query(query, param, (err, row) => {
+            if (err || row.length == 0) return rt.err(res, err, n, 'ERR8000');
+            if (row[0].c > 0) return n('ERR0063');
+        })
     })
     .all('*', rt.send);