diff --git a/Engine/include/Engine/ECS/Scene.h b/Engine/include/Engine/ECS/Scene.h
index 3cb0f98..c77e639 100644
--- a/Engine/include/Engine/ECS/Scene.h
+++ b/Engine/include/Engine/ECS/Scene.h
@@ -97,6 +97,10 @@ namespace Engine::ECS {
         // 按稳定 UUID 查实体（序列化/跨引用场景）；找不到返回 entt::null
         Entity FindEntityByUUID(UUID uuid);
 
+        // 全量重建 UUID → Entity 索引（序列化加载完调一次；运行期勿调，
+        // CreateEntity / FlushDestroyQueue 已增量维护）
+        void RebuildUuidIndex();
+
         Registry& GetRegistry() { return m_Registry; }
         const Registry& GetRegistry() const { return m_Registry; }   // 序列化等只读遍历
 
@@ -137,6 +141,12 @@ namespace Engine::ECS {
         Registry m_Registry;
         std::vector<Entity> m_PendingDestroy;
         Settings m_Settings;
+
+        // UUID → Entity 索引（O(1) FindEntityByUUID；SyncConstraints 每帧调用）
+        // CreateEntity / FlushDestroyQueue 增量维护；序列化加载后由
+        // RebuildUuidIndex() 全量重建一次（SceneSerializer 直接改 IdComponent.uuid
+        // 绕过 CreateEntity，仅靠增量会不同步）
+        std::unordered_map<UUID, Entity> m_UUIDToEntity;
     };
 
 } // namespace Engine::ECS
diff --git a/Engine/include/Engine/Physics/PhysicsWorld.h b/Engine/include/Engine/Physics/PhysicsWorld.h
index 74eac42..f686800 100644
--- a/Engine/include/Engine/Physics/PhysicsWorld.h
+++ b/Engine/include/Engine/Physics/PhysicsWorld.h
@@ -39,6 +39,7 @@
 #include <glm/gtc/quaternion.hpp>
 #include <mutex>
 #include <unordered_map>
+#include <unordered_set>
 #include <vector>
 
 namespace Engine {
@@ -126,7 +127,7 @@ namespace Engine {
                         ECS::TransformComponent& tr);
         // 约束对账：owner 孤儿清理 / body 重建传染失效 / 建缺失与变更重建
         // invalidated = 本帧 SyncScene 中被销毁或重建 body 的实体位模式
-        void SyncConstraints(const std::vector<u32>& invalidated);
+        void SyncConstraints(const std::unordered_set<u32>& invalidated);
         void CreateConstraint(u32 ownerBits, u32 targetBits,
                               const ECS::JointComponent& jc);
         void RemoveConstraint(u32 ownerBits);
diff --git a/Engine/src/ECS/Scene.cpp b/Engine/src/ECS/Scene.cpp
index ad1b364..ace7570 100644
--- a/Engine/src/ECS/Scene.cpp
+++ b/Engine/src/ECS/Scene.cpp
@@ -17,21 +17,30 @@ namespace Engine::ECS {
     {
         Entity e = m_Registry.create();
         // 出生即有：UUID（稳定身份）+ Transform（空间存在性，Unity 语义）
-        m_Registry.emplace<IdComponent>(e, IdComponent{UUID::New()});
+        const auto& id = m_Registry.emplace<IdComponent>(e, IdComponent{UUID::New()});
         m_Registry.emplace<TransformComponent>(e);
         m_Registry.emplace<NameComponent>(e, NameComponent{std::move(name)});
+        m_UUIDToEntity.emplace(id.uuid, e);
         return EntityHandle{this, e};
     }
 
     Entity Scene::FindEntityByUUID(UUID uuid)
     {
         if (!uuid.Valid()) return entt::null;
+        const auto it = m_UUIDToEntity.find(uuid);
+        // 防御：实体可能已销毁（map 仍残留过时项），二次校验 valid
+        if (it == m_UUIDToEntity.end() || !m_Registry.valid(it->second)) {
+            return entt::null;
+        }
+        return it->second;
+    }
 
-        Entity found = entt::null;
-        m_Registry.view<IdComponent>().each([&](Entity e, IdComponent& id) {
-            if (found == entt::null && id.uuid == uuid) found = e;
-        });
-        return found;
+    void Scene::RebuildUuidIndex() {
+        m_UUIDToEntity.clear();
+        m_Registry.view<IdComponent>().each(
+            [&](Entity e, const IdComponent& id) {
+                m_UUIDToEntity.emplace(id.uuid, e);
+            });
     }
 
     void Scene::DestroyEntity(Entity e)
@@ -70,6 +79,12 @@ namespace Engine::ECS {
                     std::remove(siblings.begin(), siblings.end(), e),
                     siblings.end());
             }
+
+            // 销毁前先从 UUID 索引摘掉（销毁后实体不可访问）
+            if (const auto* id = m_Registry.try_get<IdComponent>(e)) {
+                m_UUIDToEntity.erase(id->uuid);
+            }
+
             m_Registry.destroy(e);   // entt 自动回收槽位并递增版本号
         }
         m_PendingDestroy.clear();
@@ -81,6 +96,7 @@ namespace Engine::ECS {
         //（registry.clear() 后队列里的句柄全部失效，直接丢弃即可）
         m_PendingDestroy.clear();
         m_Registry.clear();
+        m_UUIDToEntity.clear();
     }
 
     EntityHandle Scene::GetEntityHandle(Entity e)
diff --git a/Engine/src/Physics/PhysicsWorld.cpp b/Engine/src/Physics/PhysicsWorld.cpp
index 735cc43..3b09e4f 100644
--- a/Engine/src/Physics/PhysicsWorld.cpp
+++ b/Engine/src/Physics/PhysicsWorld.cpp
@@ -343,7 +343,7 @@ namespace Engine {
     void PhysicsWorld::SyncScene() {
         auto &reg = m_Scene.GetRegistry();
         auto &bi = m_System->GetBodyInterface();
-        std::vector<u32> invalidated; // 本帧销毁/重建 body → 约束失效传染
+        std::unordered_set<u32> invalidated; // 本帧销毁/重建 body → 约束失效传染
 
         // 1. 孤儿清理：实体销毁 / 组件被移除 → 移除 body
         for (auto it = m_Bodies.begin(); it != m_Bodies.end();) {
@@ -353,7 +353,7 @@ namespace Engine {
                 bi.RemoveBody(it->second.id);
                 bi.DestroyBody(it->second.id);
                 m_BodyToEntity.erase(it->second.id.GetIndexAndSequenceNumber());
-                invalidated.push_back(it->first);
+                invalidated.insert(it->first);
                 it = m_Bodies.erase(it);
             } else {
                 ++it;
@@ -373,7 +373,7 @@ namespace Engine {
                     bi.DestroyBody(found->second.id);
                     m_BodyToEntity.erase(found->second.id.GetIndexAndSequenceNumber());
                     m_Bodies.erase(found);
-                    invalidated.push_back(bits);
+                    invalidated.insert(bits);
                 }
                 rb.bodyValid = false;
                 continue;
@@ -385,7 +385,7 @@ namespace Engine {
                     bi.DestroyBody(found->second.id);
                     m_BodyToEntity.erase(found->second.id.GetIndexAndSequenceNumber());
                     m_Bodies.erase(found);
-                    invalidated.push_back(bits);
+                    invalidated.insert(bits);
                 }
                 CreateBody(bits, rb, tr);
                 continue;
@@ -407,7 +407,7 @@ namespace Engine {
                 bi.DestroyBody(rec.id);
                 m_BodyToEntity.erase(found->second.id.GetIndexAndSequenceNumber());
                 m_Bodies.erase(found);
-                invalidated.push_back(bits);
+                invalidated.insert(bits);
                 rb.bodyValid = false;
                 CreateBody(bits, rb, tr);
                 continue;
@@ -456,11 +456,10 @@ namespace Engine {
 
     // ---- 约束对账 ----
 
-    void PhysicsWorld::SyncConstraints(const std::vector<u32> &invalidated) {
+    void PhysicsWorld::SyncConstraints(const std::unordered_set<u32> &invalidated) {
         auto &reg = m_Scene.GetRegistry();
-        const auto tainted = [&invalidated](u32 bits) {
-            return std::find(invalidated.begin(), invalidated.end(), bits)
-                   != invalidated.end();
+        const auto tainted = [&invalidated](const u32 bits) {
+                   return invalidated.count(bits);
         };
 
         // 1. owner 实体/组件没了（或被禁用），或任一端 body 本帧被销毁/重建 → 移除
@@ -901,6 +900,7 @@ namespace Engine {
         rb.bodyValid = true;
     }
 
+
     void PhysicsWorld::RemoveBody(const u32 entityBits) {
         const auto found = m_Bodies.find(entityBits);
         if (found == m_Bodies.end()) return;
diff --git a/Engine/src/Serialization/SceneSerializer.cpp b/Engine/src/Serialization/SceneSerializer.cpp
index 83d8066..155687a 100644
--- a/Engine/src/Serialization/SceneSerializer.cpp
+++ b/Engine/src/Serialization/SceneSerializer.cpp
@@ -767,6 +767,10 @@ namespace Engine::Serialization {
         // 显式补算，否则首帧 World = 单位阵
         scene.UpdateTransforms();
 
+        // 序列化加载绕过了 CreateEntity 的 UUID 增量维护（565 行直接覆盖
+        // IdComponent.uuid），全量重建一次索引，否则 FindEntityByUUID 会全失效
+        scene.RebuildUuidIndex();
+
         ENGINE_INFO("SceneSerializer: loaded {} entities from '{}'",
                     parsed.size(), sourceName);
         return true;