diff --git a/ui/web/src/i18n/locales/en/login.json b/ui/web/src/i18n/locales/en/login.json
index c803de65..27c02ca1 100644
--- a/ui/web/src/i18n/locales/en/login.json
+++ b/ui/web/src/i18n/locales/en/login.json
@@ -13,6 +13,7 @@
   "token": {
     "userId": "User ID",
     "userIdPlaceholder": "your-user-id",
+    "userIdHint": "Use \"system\" for full system access",
     "gatewayToken": "Gateway Token",
     "tokenPlaceholder": "Bearer token",
     "connect": "Connect",
diff --git a/ui/web/src/i18n/locales/vi/login.json b/ui/web/src/i18n/locales/vi/login.json
index 795f3c1f..289c81b0 100644
--- a/ui/web/src/i18n/locales/vi/login.json
+++ b/ui/web/src/i18n/locales/vi/login.json
@@ -33,7 +33,8 @@
     "gatewayToken": "Gateway Token",
     "tokenPlaceholder": "Bearer token",
     "userId": "User ID",
-    "userIdPlaceholder": "your-user-id"
+    "userIdPlaceholder": "your-user-id",
+    "userIdHint": "Dùng \"system\" để có toàn quyền hệ thống"
   },
   "noAccessHint": "Yêu cầu quản trị viên thêm bạn vào tenant, hoặc đăng nhập bằng tài khoản khác.",
   "logout": "Đăng xuất"
diff --git a/ui/web/src/i18n/locales/zh/login.json b/ui/web/src/i18n/locales/zh/login.json
index 0172b984..eb7307fe 100644
--- a/ui/web/src/i18n/locales/zh/login.json
+++ b/ui/web/src/i18n/locales/zh/login.json
@@ -33,7 +33,8 @@
     "gatewayToken": "Gateway Token",
     "tokenPlaceholder": "Bearer token",
     "userId": "用户 ID",
-    "userIdPlaceholder": "您的用户 ID"
+    "userIdPlaceholder": "您的用户 ID",
+    "userIdHint": "使用 \"system\" 获取完整系统权限"
   },
   "noAccessHint": "请联系管理员将您添加到租户，或使用其他账号登录。",
   "logout": "退出登录"
diff --git a/ui/web/src/pages/login/token-form.tsx b/ui/web/src/pages/login/token-form.tsx
index 2036c632..ee1a12a1 100644
--- a/ui/web/src/pages/login/token-form.tsx
+++ b/ui/web/src/pages/login/token-form.tsx
@@ -8,7 +8,7 @@ interface TokenFormProps {
 
 export function TokenForm({ onSubmit }: TokenFormProps) {
   const { t } = useTranslation("login");
-  const [userId, setUserId] = useState("");
+  const [userId, setUserId] = useState("system");
   const [token, setToken] = useState("");
   const [connecting, setConnecting] = useState(false);
   const [error, setError] = useState<string | null>(null);
@@ -63,6 +63,9 @@ export function TokenForm({ onSubmit }: TokenFormProps) {
           autoFocus
           disabled={connecting}
         />
+        <p className="text-xs text-muted-foreground">
+          {t("token.userIdHint")}
+        </p>
       </div>
 
       <div className="space-y-2">