diff --git a/webapp/controller/ShopController.class.php b/webapp/controller/ShopController.class.php
index 429b66d9..b6b85992 100644
--- a/webapp/controller/ShopController.class.php
+++ b/webapp/controller/ShopController.class.php
@@ -1164,10 +1164,27 @@ class ShopController extends BaseAuthedController
             $this->_rspErr(2, 'id is invalid');
             return;
         }
+        $isFreeBuy = false;
+        if (!empty($shop['free_type'])) {
+            $count = $this->countFreeBuyTimes($shop);
+            if ($count < $shop['free_num']) {
+                $isFreeBuy = true;
+            }
+        }
         $cost = $shop['price'] * $num;
+        if ($isFreeBuy) {
+            $cost = 0;
+        }
+
         $recommend = $shop['recommend'];
 
         $itemStore = mt\ShopChest::getRandomItemListByChestType($recommend);
+        if ($isFreeBuy) {
+            if ($num != 1) {
+                $this->_rspErr(2, 'num is invalid');
+                return;
+            }
+        }
 
         $result = array();
         for ($i = 0; $i < $num; $i++) {
@@ -1186,6 +1203,9 @@ class ShopController extends BaseAuthedController
                 $record[$key] = array("item_id" => $item['item_id'], "item_num" => $item['num']);
                 array_push($result, $record[$key]);
             }
+            if ($isFreeBuy && $num == 1) {
+                $this->addFreeBuyRecord($shop);    
+            }
         }
 
         error_log("buyBlindBox start " . json_encode(