diff --git a/logic/GameClass/GameObj/Character/Character.cs b/logic/GameClass/GameObj/Character/Character.cs
index 7b9fc48..1d6ab0e 100644
--- a/logic/GameClass/GameObj/Character/Character.cs
+++ b/logic/GameClass/GameObj/Character/Character.cs
@@ -13,6 +13,8 @@ namespace GameClass.GameObj
         public ReaderWriterLockSlim HPReadWriterLock => hpReaderWriterLock;
         private readonly object vampireLock = new();
         public object VampireLock => vampire;
+        private readonly object inventoryLock = new();
+        public object InventoryLock => inventoryLock;
 
         #region 装弹、攻击相关的基本属性及方法
         /// <summary>
@@ -572,14 +574,15 @@ namespace GameClass.GameObj
                                                 {new NullProp(), new NullProp(),new NullProp() };
         public Gadget[] PropInventory
         {
-            get => propInventory;
+            get
+            {
+                lock (inventoryLock)
+                    return propInventory;
+            }
             set
             {
-                lock (gameObjLock)
-                {
+                lock (inventoryLock)
                     propInventory = value;
-                    Debugger.Output(this, " prop becomes " + (PropInventory == null ? "null" : PropInventory.ToString()));
-                }
             }
         }
 
@@ -591,9 +594,10 @@ namespace GameClass.GameObj
         {
             if (indexing < 0 || indexing >= GameData.maxNumOfPropInPropInventory)
                 return new NullProp();
-            lock (gameObjLock)
+            lock (inventoryLock)
             {
                 Gadget prop = propInventory[indexing];
+                if (!prop.IsUsable()) return new NullProp();
                 PropInventory[indexing] = new NullProp();
                 return prop;
             }
@@ -601,13 +605,13 @@ namespace GameClass.GameObj
 
         public Gadget UseProp(PropType propType)
         {
-            lock (gameObjLock)
+            if (propType == PropType.Null)
             {
-                if (propType == PropType.Null)
+                lock (inventoryLock)
                 {
                     for (int indexing = 0; indexing < GameData.maxNumOfPropInPropInventory; ++indexing)
                     {
-                        if (PropInventory[indexing].GetPropType() != PropType.Null)
+                        if (PropInventory[indexing].IsUsable())
                         {
                             Gadget prop = PropInventory[indexing];
                             PropInventory[indexing] = new NullProp();
@@ -615,18 +619,23 @@ namespace GameClass.GameObj
                         }
                     }
                 }
-                else
+            }
+            else
+            {
+                lock (inventoryLock)
+                {
                     for (int indexing = 0; indexing < GameData.maxNumOfPropInPropInventory; ++indexing)
                     {
-                        if (PropInventory[indexing].GetPropType() == propType)
+                        if (PropInventory[indexing].GetPropType() == propType && PropInventory[indexing].IsUsable())
                         {
                             Gadget prop = PropInventory[indexing];
                             PropInventory[indexing] = new NullProp();
                             return prop;
                         }
                     }
-                return new NullProp();
+                }
             }
+            return new NullProp();
         }
 
         /// <summary>
@@ -635,9 +644,10 @@ namespace GameClass.GameObj
         public int IndexingOfAddProp()
         {
             int indexing = 0;
-            for (; indexing < GameData.maxNumOfPropInPropInventory; ++indexing)
-                if (PropInventory[indexing].GetPropType() == PropType.Null)
-                    break;
+            lock (inventoryLock)
+                for (; indexing < GameData.maxNumOfPropInPropInventory; ++indexing)
+                    if (propInventory[indexing].GetPropType() == PropType.Null)
+                        break;
             return indexing;
         }
 
diff --git a/logic/GameClass/GameObj/Prop/Gadget.cs b/logic/GameClass/GameObj/Prop/Gadget.cs
index 6427b27..e9a94e2 100644
--- a/logic/GameClass/GameObj/Prop/Gadget.cs
+++ b/logic/GameClass/GameObj/Prop/Gadget.cs
@@ -18,6 +18,7 @@ namespace GameClass.GameObj
 
         public override ShapeType Shape => ShapeType.Square;
 
+        public abstract bool IsUsable();
         public abstract PropType GetPropType();
 
         public Gadget(XY initPos, int radius = GameData.PropRadius) :
@@ -45,10 +46,12 @@ namespace GameClass.GameObj
                 }
             }
         }
+        public override bool IsUsable() => !IsUsed;
         public Tool(XY initPos) : base(initPos) { }
     }
     public abstract class Consumables : Gadget
     {
+        public override bool IsUsable() => true;
         public Consumables(XY initPos) : base(initPos) { }
     }
 
@@ -134,6 +137,7 @@ namespace GameClass.GameObj
     }
     public sealed class NullProp : Gadget
     {
+        public override bool IsUsable() => false;
         public NullProp() : base(new XY(1, 1))
         {
         }
diff --git a/logic/Gaming/PropManager.cs b/logic/Gaming/PropManager.cs
index 994fd82..abb5866 100644
--- a/logic/Gaming/PropManager.cs
+++ b/logic/Gaming/PropManager.cs
@@ -73,8 +73,7 @@ namespace Gaming
             /// <returns></returns>
             public bool PickProp(Character player, PropType propType = PropType.Null)
             {
-                if (player.IsRemoved)
-                    return false;
+                if (!player.Commandable()) return false;
                 int indexing = player.IndexingOfAddProp();
                 if (indexing == GameData.maxNumOfPropInPropInventory)
                     return false;