diff --git a/extend/chat/model/Base.php b/extend/chat/model/Base.php
index 65c12c5..938bf8a 100644
--- a/extend/chat/model/Base.php
+++ b/extend/chat/model/Base.php
@@ -215,7 +215,7 @@ namespace extend\chat\model;
              'content' => !empty($message['content'])?$message['content']:null,
              'image_url' => !empty($message['image_url'])?$message['image_url']:null,
              'order_id' => !empty($message['order_id'])?$message['order_id']:null,
-             'coupon' => !empty($message['coupon'])?$message['coupon']:null,
+             'coupon' => !empty($message['coupon'])?json_encode($message['coupon']):null,
              'send_time' => $time,
              'session_id' => $session_id,
          ];