diff --git a/webapp/services/MissionService.php b/webapp/services/MissionService.php
index 94754503..ae5591c8 100644
--- a/webapp/services/MissionService.php
+++ b/webapp/services/MissionService.php
@@ -25,7 +25,6 @@ use models\Gun;
   offer.reward.missions
   {
   "refreshtime": 0,
-  "count": 0,
   "missions": [
   {
     "mission_id": 100,
@@ -84,12 +83,7 @@ class MissionService extends BaseService {
                 'missions' => array()
             );
         }
-        {
-            $refreshTime = getXVal($this->offerRewartdMission, 'refreshtime');
-            if (myself()->_getNowDaySeconds() > $refreshTime) {
-                $this->refreshOfferRewardMission();
-            }
-        }
+        $this->refreshOfferRewardMission();
     }
 
     public function getMissionDto($userInfo, $seasonDb, $missionDb, $missionMeta)
@@ -558,25 +552,26 @@ class MissionService extends BaseService {
 
     private function refreshOfferRewardMission()
     {
-        $this->offerRewartdMission['refreshtime'] = myself()->_getNowTime();
-        $sentMissions = array();
-        foreach ($this->offerRewartdMission['missions'] as $mission) {
-            if ($mission['sendtime'] > 0) {
-                array_push($sentMissions, $mission);
-            }
+        $wantedRefreshMissionNum = mt\Parameter::getVal
+                                 ('wanted_refresh_mission_num', 0);
+        if ($wantedRefreshMissionNum <=
+            count($this->offerRewartdMission['missions'])) {
+            return;
         }
-        if (empty($this->offerRewartdMission['missions'])) {
-            $this->offerRewartdMission['missions'] = array();
+        $metas = mt\Task::getOfferRewardMissions
+               ($this->offerRewartdMission['missions']);
+        if (count($metas) < $wantedRefreshMissionNum) {
+            return;
         }
-        $metas = mt\Task::getOfferRewardMissions($this->offerRewartdMission['missions']);
-        $num = min(count($metas), mt\Parameter::getVal('wanted_refresh_mission_num', 0));
-        if ($num > 0) {
-            $selectKeys = array_rand($metas, $num);
-            if (!is_array($selectKeys)) {
-                $selectKeys = array($selectKeys);
+
+        foreach (array_rand($metas, count($metas)) as $key) {
+            if (count($this->offerRewartdMission['missions']) >=
+                $wantedRefreshMissionNum) {
+                break;
             }
-            foreach ($selectKeys as $key) {
-                $meta = $metas[$key];
+            $meta = $metas[$key];
+            $found = false;
+            if (!$found) {
                 array_push($this->offerRewartdMission['missions'],
                            array(
                                'mission_id' => $meta['id'],
@@ -587,7 +582,7 @@ class MissionService extends BaseService {
                            ));
             }
         }
-        $this->offerRewartdMission['count'] = $num;
+        $this->offerRewartdMission['refreshtime'] = myself()->_getNowTime();
         $this->saveOfferRewardMission();
     }
 
@@ -877,8 +872,8 @@ class MissionService extends BaseService {
 
     public function getOfferRewardMissionCount()
     {
-        $count = getXVal($this->offerRewartdMission, 'count');
-        return $count;
+        $missions = getXVal($this->offerRewartdMission, 'missions', array());
+        return count($missions);
     }
 
 }