diff --git a/WeChat/Contracts/Tools.php b/WeChat/Contracts/Tools.php
index 4cfe9b8..a9bf0a9 100644
--- a/WeChat/Contracts/Tools.php
+++ b/WeChat/Contracts/Tools.php
@@ -155,7 +155,7 @@ class Tools
     {
         return preg_replace_callback('/\\\\u([0-9a-f]{4})/i', function ($matches) {
             return mb_convert_encoding(pack("H*", $matches[1]), "UTF-8", "UCS-2BE");
-        }, json_encode($data));
+        }, ($jsonData = json_encode($data)) == '[]' ? '{}' : $jsonData);
     }
 
     /**