diff --git a/src/plugin_runtime/runner/plugin_loader.py b/src/plugin_runtime/runner/plugin_loader.py
index 97ab3284..9efe184d 100644
--- a/src/plugin_runtime/runner/plugin_loader.py
+++ b/src/plugin_runtime/runner/plugin_loader.py
@@ -9,6 +9,7 @@
 from collections import deque
 from typing import Any, Dict, List, Optional, Set, Tuple
 
+import contextlib
 import importlib
 import importlib.util
 import json
@@ -239,7 +240,19 @@ class PluginLoader:
 
         module = importlib.util.module_from_spec(spec)
         sys.modules[module_name] = module
-        spec.loader.exec_module(module)
+
+        plugin_parent_dir = os.path.dirname(plugin_dir)
+        inserted_plugin_parent = False
+        if plugin_parent_dir and plugin_parent_dir not in sys.path:
+            sys.path.insert(0, plugin_parent_dir)
+            inserted_plugin_parent = True
+
+        try:
+            spec.loader.exec_module(module)
+        finally:
+            if inserted_plugin_parent:
+                with contextlib.suppress(ValueError):
+                    sys.path.remove(plugin_parent_dir)
 
         # 优先使用新版 create_plugin 工厂函数
         create_plugin = getattr(module, "create_plugin", None)
diff --git a/src/plugin_runtime/runner/runner_main.py b/src/plugin_runtime/runner/runner_main.py
index 245a5487..dae1cfa1 100644
--- a/src/plugin_runtime/runner/runner_main.py
+++ b/src/plugin_runtime/runner/runner_main.py
@@ -627,14 +627,19 @@ def _isolate_sys_path(plugin_dirs: List[str]) -> None:
             allowed.add(p)
 
     # 添加插件目录
-    for d in plugin_dirs:
-        allowed.add(os.path.normpath(d))
+    plugin_dir_paths = [os.path.normpath(d) for d in plugin_dirs]
+    for d in plugin_dir_paths:
+        allowed.add(d)
 
     # 添加项目根目录（使得 src.plugin_runtime / src.common 可导入）
     runtime_root = os.path.normpath(os.path.join(os.path.dirname(__file__), "..", "..", ".."))
     allowed.add(runtime_root)
 
-    sys.path[:] = [p for p in sys.path if p in allowed]
+    preserved_paths = [p for p in sys.path if p in allowed]
+    for extra_path in [*plugin_dir_paths, runtime_root]:
+        if extra_path not in preserved_paths:
+            preserved_paths.append(extra_path)
+    sys.path[:] = preserved_paths
 
     # 安装 import 钩子，阻止插件导入主程序核心模块
     # 仅允许 src.plugin_runtime 和 src.common，拒绝其他 src.* 子包