diff --git a/app/common/service/UsedCarService.php b/app/common/service/UsedCarService.php
index 3b26bbf..804c980 100644
--- a/app/common/service/UsedCarService.php
+++ b/app/common/service/UsedCarService.php
@@ -141,7 +141,11 @@ class UsedCarService
         $asc = ord($s[0]);
 
         if ($asc >= 65 && $asc <= 90) return $char;
-
+        
+    // 转码失败或长度不足
+    if ($s === false || strlen($s) < 2) {
+        return '';
+    }
         $code = ord($s[0]) * 256 + ord($s[1]) - 65536;
 
         $map = [