diff --git a/behavior_pack_v8jz0zSR/Script_NeteaseModousIY5aSF/BlueFoxTools/SpecialFunciton/BlueFoxRuckSackEngine.py b/behavior_pack_v8jz0zSR/Script_NeteaseModousIY5aSF/BlueFoxTools/SpecialFunciton/BlueFoxRuckSackEngine.py
index 40643ab..792fd02 100644
--- a/behavior_pack_v8jz0zSR/Script_NeteaseModousIY5aSF/BlueFoxTools/SpecialFunciton/BlueFoxRuckSackEngine.py
+++ b/behavior_pack_v8jz0zSR/Script_NeteaseModousIY5aSF/BlueFoxTools/SpecialFunciton/BlueFoxRuckSackEngine.py
@@ -555,7 +555,10 @@ class RucksackScreen(baseScreen):
         :param destinationSlot: 目标物品槽位
         :return:
         """
-        itemDict1, itemDict2 = DeclareItemAnyNum(self.items[originSlot], 64 - self.items[destinationSlot]['count'])
+        itemInfo = GetItemBaseInfoSafely(self.items[originSlot])
+        maxStack = (itemInfo or {}).get('maxStackSize') or 64
+        itemDict1, itemDict2 = DeclareItemAnyNum(
+            self.items[originSlot], maxStack - self.items[destinationSlot]['count'])
         self.SetItemAbs(originSlot, itemDict1)
         return itemDict2
 
diff --git a/behavior_pack_v8jz0zSR/Script_NeteaseModousIY5aSF/BlueFoxTools/SpecialFunciton/BlueFoxSystem.py b/behavior_pack_v8jz0zSR/Script_NeteaseModousIY5aSF/BlueFoxTools/SpecialFunciton/BlueFoxSystem.py
index 78871a9..ceb6a04 100644
--- a/behavior_pack_v8jz0zSR/Script_NeteaseModousIY5aSF/BlueFoxTools/SpecialFunciton/BlueFoxSystem.py
+++ b/behavior_pack_v8jz0zSR/Script_NeteaseModousIY5aSF/BlueFoxTools/SpecialFunciton/BlueFoxSystem.py
@@ -773,7 +773,8 @@ class BlueFoxServerSystem(serverBaseSystem):
     # ============================================================================
     # 统一"主动获得物品"接口(任务一):
     #   所有给玩家的物品一律按优先级分发, 而非直接掉落:
-    #   1) 背包(0~35格)存在同类且未堆满(64) -> 数量 +count 合并
+    #   1) 背包(0~35格)存在同类且未堆满(按物品真实堆叠上限) -> 数量 +count 合并
+    #      (上限<=1 的物品如水桶/工具不合并, 由 2/3/4 步处理)
     #   2) 主手为空 -> 放到主手
     #   3) 主手有物 -> 放入背包(同类叠加/空位)
     #   4) 背包满且主手有物 -> 掉落物形式(在 pos 上方生成)
@@ -832,14 +833,31 @@ class BlueFoxServerSystem(serverBaseSystem):
                 pass
         return False
 
+    def _getItemMaxStack(self, itemName, aux=0):
+        """取物品真实的堆叠上限。取不到时回退 64(与原行为一致, 保证未知物品仍可合并)。"""
+        try:
+            info = serverCompFactory.CreateItem(LevelId).GetItemBasicInfo(
+                itemName, aux, False)
+            size = (info or {}).get("maxStackSize")
+            if size:
+                return int(size)
+        except Exception:
+            pass
+        return 64
+
     def _mergeSameStackInv(self, playerId, itemName, count=1, aux=0):
-        """把 count 个 (itemName, aux) 合并进背包(0~35格)里已有的同类堆叠(未满64)。
+        """把 count 个 (itemName, aux) 合并进背包(0~35格)里已有的同类堆叠(未满真实上限)。
         返回"剩余没能合并的数量"(0 = 全部并进了已有堆叠)。
+        上限取物品真实 maxStackSize, 上限<=1 的物品(水桶/工具等)一律不合并,
+        交由后续主手/背包(引擎接口)/掉落处理, 避免出现"一格被叠成多个"。
         读写用本工程已验证可用的 GetPlayerAllItems(0) + SetInvItemNum
         (参考 FastComp.DeclarePlayerInvItem); 逐格独立 try 保护, 单格异常不影响其它格。"""
         remain = count
         if remain <= 0:
             return 0
+        maxStack = self._getItemMaxStack(itemName, aux)
+        if maxStack <= 1:
+            return remain
         try:
             itemComp = serverCompFactory.CreateItem(playerId)
             allItems = itemComp.GetPlayerAllItems(0)   # 0 = ItemPosType.INVENTORY(0~35)
@@ -857,9 +875,9 @@ class BlueFoxServerSystem(serverBaseSystem):
                 if (d.get("newAuxValue") or 0) != aux:
                     continue
                 cur = d.get("count") or 0
-                if cur <= 0 or cur >= 64:
+                if cur <= 0 or cur >= maxStack:
                     continue
-                add = min(64 - cur, remain)
+                add = min(maxStack - cur, remain)
                 if itemComp.SetInvItemNum(index, cur + add):
                     remain -= add
             except Exception: