diff --git a/server/gameserver/creature.cc b/server/gameserver/creature.cc
index acc1564..a38eec7 100644
--- a/server/gameserver/creature.cc
+++ b/server/gameserver/creature.cc
@@ -869,10 +869,7 @@ void Creature::ProcBuffEffect(Creature* caster, Buff* buff)
     case kBET_SummonHero:
         {
             if (!dead) {
-                SummonHero(buff,
-                           GetPos(),
-                           GetMoveDir(),
-                           buff->meta->hero_infos);
+                SummonHero(buff, GetPos(), GetMoveDir());
             }
         }
         break;
@@ -1509,8 +1506,12 @@ void Creature::CheckSpecObject()
     #endif
 }
 
-RoomObstacle* Creature::SummonObstacle(Buff* buff, int id, const a8::Vec2& pos)
+void Creature::SummonObstacle(Buff* buff, int id, const a8::Vec2& pos)
 {
+    buff->meta->int_param2 = 2;
+    if (buff->meta->int_param2 > 0) {
+        RemoveSurplusObstacle(buff->meta->i->buff_id(), id, buff->meta->int_param2);
+    }
     RoomObstacle* obstacle = room->CreateObstacle(id, pos.x, pos.y);
     if (obstacle) {
         obstacle->master.Attach(this);
@@ -1521,7 +1522,6 @@ RoomObstacle* Creature::SummonObstacle(Buff* buff, int id, const a8::Vec2& pos)
     } else {
         abort();
     }
-    return obstacle;
 }
 
 bool Creature::CollisonDetection()
@@ -1645,14 +1645,15 @@ void Creature::ResetAllSkillCd()
 
 void Creature::SummonHero(Buff* buff,
                           const a8::Vec2& pos,
-                          const a8::Vec2& dir,
-                          std::vector<std::tuple<int, float, float, int>>& infos)
+                          const a8::Vec2& dir
+                          )
 {
-    for (auto& info : infos) {
+    for (auto& info : buff->meta->hero_infos) {
         int through_wall = std::get<0>(info);
         float x = std::get<1>(info);
         float y = std::get<2>(info) ;
         int hero_id = std::get<3>(info);
+        int num = std::get<4>(info);
         MetaData::Player* hero_meta = MetaMgr::Instance()->GetPlayer(hero_id);
         if (hero_meta && !dead) {
             for (int i = 0; i < 4; ++i) {
@@ -1671,6 +1672,7 @@ void Creature::SummonHero(Buff* buff,
                      hero_pos,
                      &collider
                      )) {
+                    RemoveSurplusHero(buff->meta->i->buff_id(), hero_id, num);
                     Hero* hero = room->CreateHero
                         (this,
                          hero_meta,
diff --git a/server/gameserver/creature.h b/server/gameserver/creature.h
index 2aca8d7..b534a3f 100644
--- a/server/gameserver/creature.h
+++ b/server/gameserver/creature.h
@@ -153,11 +153,8 @@ class Creature : public MoveableEntity
 
     void CheckSpecObject();
     bool CollisonDetection();
-    RoomObstacle* SummonObstacle(Buff* buff, int id, const a8::Vec2& pos);
-    void SummonHero(Buff* buff,
-                    const a8::Vec2& pos,
-                    const a8::Vec2& dir,
-                    std::vector<std::tuple<int, float, float, int>>& infos);
+    void SummonObstacle(Buff* buff, int id, const a8::Vec2& pos);
+    void SummonHero(Buff* buff, const a8::Vec2& pos, const a8::Vec2& dir);
     void FillSkillCasterState(SkillCasterState* caster_state);
     void RecoverSkillCasterState(SkillCasterState* caster_state);
     CreatureWeakPtr AllocWeakPtr();
diff --git a/server/gameserver/metadata.cc b/server/gameserver/metadata.cc
index 46864a1..3a6be1f 100644
--- a/server/gameserver/metadata.cc
+++ b/server/gameserver/metadata.cc
@@ -732,9 +732,10 @@ namespace MetaData
                     float x = a8::XValue(strings2[1]).GetDouble();
                     float y = a8::XValue(strings2[2]).GetDouble();
                     int hero_id = a8::XValue(strings2[3]);
+                    int num = strings2.size() > 4 ? a8::XValue(strings2[4]).GetInt() : 10000;
                     hero_infos.push_back
                         (
-                         std::make_tuple(through_wall, x, y, hero_id)
+                         std::make_tuple(through_wall, x, y, hero_id, num)
                          );
                 }
             }
diff --git a/server/gameserver/metadata.h b/server/gameserver/metadata.h
index 5862ac9..39aa66b 100755
--- a/server/gameserver/metadata.h
+++ b/server/gameserver/metadata.h
@@ -192,7 +192,7 @@ namespace MetaData
         std::vector<std::tuple<int, std::vector<std::tuple<int, int>>>> batch_add_list;
         std::vector<std::tuple<int, std::vector<int>>> post_remove_action;
         std::set<int> immune_buffeffect;
-        std::vector<std::tuple<int, float, float, int>> hero_infos;
+        std::vector<std::tuple<int, float, float, int, int>> hero_infos;
     };
 
     struct SkillPhase
diff --git a/server/gameserver/obstacle.h b/server/gameserver/obstacle.h
index 9387a2c..de88ad2 100644
--- a/server/gameserver/obstacle.h
+++ b/server/gameserver/obstacle.h
@@ -54,7 +54,7 @@ class Obstacle : public Entity
     void IncDoorOpenTimes(Room* room);
     float GetHealth(Room* room);
     void SetHealth(Room* room, float value);
-    void Die(Room* room);
+    virtual void Die(Room* room);
     int GetTeamId(Room* room);
     void SetTeamId(Room* room, int team_id);
     int GetMasterId(Room* room);
diff --git a/server/gameserver/room.cc b/server/gameserver/room.cc
index 7a15df0..0bee13a 100644
--- a/server/gameserver/room.cc
+++ b/server/gameserver/room.cc
@@ -636,48 +636,65 @@ Hero* Room::CreateHero(Creature* master,
 }
 
 void Room::RemoveObjectLater(RoomEntity* entity)
+{
+    InternalRemoveObjectLater(entity, entity->xtimer_attacher);
+}
+
+void Room::RemoveObjectLater(RoomObstacle* entity)
+{
+    InternalRemoveObjectLater(entity, entity->xtimer_attacher);
+}
+
+void Room::InternalRemoveObjectLater(Entity* entity, a8::XTimerAttacher& xtimer_attacher)
 {
     auto remove_func =
         [] (const a8::XParams& param)
         {
-            RoomEntity* entity = (RoomEntity*)param.sender.GetUserData();
+            Entity* entity = (Entity*)param.sender.GetUserData();
+            Room* room = (Room*)param.param1.GetUserData();
             switch (entity->GetEntityType()) {
             case ET_Bullet:
                 {
-                    entity->room->RemoveFromMoveableHash((Bullet*)entity);
-                    entity->room->grid_service->DelBullet((Bullet*)entity);
+                    room->RemoveFromMoveableHash((Bullet*)entity);
+                    room->grid_service->DelBullet((Bullet*)entity);
                 }
                 break;
             case ET_Loot:
                 {
-                    entity->BroadcastDeleteState(entity->room);
-                    entity->room->grid_service->DelRoomEntity(entity->room, entity);
+                    entity->BroadcastDeleteState(room);
+                    room->grid_service->DelRoomEntity(room, entity);
                 }
                 break;
             case ET_Player:
                 {
-                    entity->room->RemoveFromMoveableHash((Human*)entity);
-                    entity->room->RemoveFromHuamnHash((Human*)entity);
+                    room->RemoveFromMoveableHash((Human*)entity);
+                    room->RemoveFromHuamnHash((Human*)entity);
                 }
                 break;
             case ET_Car:
                 {
                     #if 0
-                    entity->RemoveFromAroundPlayers(entity->room);
-                    entity->BroadcastDeleteState(entity->room);
-                    entity->room->grid_service->RemoveCreature((Car*)entity);
+                    RemoveFromAroundPlayers(entity->room);
+                    BroadcastDeleteState(entity->room);
+                    room->grid_service->RemoveCreature((Car*)entity);
                     #endif
-                    entity->room->RemoveFromMoveableHash((Car*)entity);
+                    room->RemoveFromMoveableHash((Car*)entity);
                 }
                 break;
             case ET_Hero:
                 {
                     #if 0
-                    entity->BroadcastDeleteState(entity->room);
-                    entity->RemoveFromAroundPlayers(entity->room);
-                    entity->room->grid_service->RemoveCreature((Hero*)entity);
+                    BroadcastDeleteState(entity->room);
+                    RemoveFromAroundPlayers(entity->room);
+                    room->grid_service->RemoveCreature((Hero*)entity);
                     #endif
-                    entity->room->RemoveFromMoveableHash((Hero*)entity);
+                    room->RemoveFromMoveableHash((Hero*)entity);
+                }
+                break;
+            case ET_Obstacle:
+                {
+                    entity->BroadcastDeleteState(room);
+                    room->grid_service->DelRoomEntity(room, entity);
                 }
                 break;
             default:
@@ -686,7 +703,7 @@ void Room::RemoveObjectLater(RoomEntity* entity)
                 }
                 break;
             }
-            entity->room->RemoveFromEntityHash(entity);
+            room->RemoveFromEntityHash(entity);
 #ifdef DEBUG
             #if 0
             a8::UdpLog::Instance()->Debug
@@ -701,11 +718,12 @@ void Room::RemoveObjectLater(RoomEntity* entity)
 #endif
             delete entity;
         };
-    xtimer.AddDeadLineTimerAndAttach(0,
+    xtimer.AddDeadLineTimerAndAttach(2,
                                      a8::XParams()
-                                     .SetSender(entity),
+                                     .SetSender(entity)
+                                     .SetParam1(this),
                                      remove_func,
-                                     &entity->xtimer_attacher.timer_list_);
+                                     &xtimer_attacher.timer_list_);
 }
 
 void Room::OnHumanDie(Human* hum)
diff --git a/server/gameserver/room.h b/server/gameserver/room.h
index 4944178..68d33ad 100644
--- a/server/gameserver/room.h
+++ b/server/gameserver/room.h
@@ -91,6 +91,7 @@ public:
     Human* FindEnemy(Human* hum);
 
     void RemoveObjectLater(RoomEntity* entity);
+    void RemoveObjectLater(RoomObstacle* entity);
 
     void FillSMJoinedNotify(Player* self_hum, cs::SMJoinedNotify& msg);
 
@@ -261,6 +262,7 @@ private:
     size_t GetRoomMaxPlayerNum();
     void InitAndroidAI();
     void ForwardGasRing(int n);
+    void InternalRemoveObjectLater(Entity* entity, a8::XTimerAttacher& entity_xtimer_attacher);
 
     #ifdef DEBUG
     void InitDebugInfo();
diff --git a/server/gameserver/roomobstacle.cc b/server/gameserver/roomobstacle.cc
index cb62bc7..d6779a5 100644
--- a/server/gameserver/roomobstacle.cc
+++ b/server/gameserver/roomobstacle.cc
@@ -31,6 +31,12 @@ RoomObstacle::~RoomObstacle()
 #endif
         room->map_service->RemoveCollider(collider);
     }
+    if (!detached_) {
+        if (master.Get()) {
+            master.Get()->SlaveOnRemove(this);
+        }
+        detached_ = true;
+    }
     if (!grid_list_) {
         A8_SAFE_DELETE(grid_list_);
     }
@@ -445,5 +451,25 @@ void RoomObstacle::ActivePosionGas()
 
 void RoomObstacle::DetachFromMaster()
 {
-
+    if (!detached_) {
+        detached_ = true;
+        if (master.Get()) {
+            xtimer_attacher.ClearTimerList();
+            master.Get()->SlaveOnRemove(this);
+            room->grid_service->DelRoomEntity(room, this);
+            if (!IsDead(room)) {
+                Die(room);
+                BroadcastFullState(room);
+            }
+            room->RemoveObjectLater(this);
+        }
+    }
+}
+
+void RoomObstacle::Die(Room* room)
+{
+    if (!IsDead(room)) {
+        Obstacle::Die(room);
+        DetachFromMaster();
+    }
 }
diff --git a/server/gameserver/roomobstacle.h b/server/gameserver/roomobstacle.h
index 4acf2eb..abf451f 100644
--- a/server/gameserver/roomobstacle.h
+++ b/server/gameserver/roomobstacle.h
@@ -22,6 +22,7 @@ class RoomObstacle : public Obstacle
     void UpdateTimerFunc();
     void Active();
     void DetachFromMaster();
+    virtual void Die(Room* room) override;
 
 private:
     void Explosion();
@@ -35,6 +36,7 @@ protected:
     bool temp_through_ = false;
     std::set<GridCell*>* grid_list_ = nullptr;
     int explosion_times_ = 0;
+    bool detached_ = false;
 
     RoomObstacle();