diff --git a/app/controller/api/store/merchant/Merchant.php b/app/controller/api/store/merchant/Merchant.php
index 826a6831..4acf62db 100644
--- a/app/controller/api/store/merchant/Merchant.php
+++ b/app/controller/api/store/merchant/Merchant.php
@@ -269,7 +269,7 @@ class Merchant extends BaseController
             return app('json')->fail('参数错误');
         }
         $margin = Db::name('MerchantType')->where('mer_type_id', $merchantInfo['type_id'])->value('margin');
-        $merchantInfo['unpaid_margin'] = bcsub($margin,$merchantInfo['paid_margin']);
+        $merchantInfo['unpaid_margin'] = bcsub($margin,$merchantInfo['paid_margin'],2);
         if($merchantInfo['margin']==0){
             $merchantInfo['margin']=$merchantInfo['unpaid_margin'];
         }