diff --git a/lazyllm/flow/flow.py b/lazyllm/flow/flow.py
index e928a145..2d8c94a0 100644
--- a/lazyllm/flow/flow.py
+++ b/lazyllm/flow/flow.py
@@ -347,11 +347,12 @@ class PostProcessType(Enum):
         SUM = 4
         JOIN = 5
 
-    def __init__(self, *args, _scatter=False, _concurrent=True, auto_capture=False, **kw):
+    def __init__(self, *args, _scatter: bool = False, _concurrent: Union[bool, int] = True,
+                 auto_capture: bool = False, **kw):
         super().__init__(*args, **kw, auto_capture=auto_capture)
         self._post_process_type = Parallel.PostProcessType.NONE
         self._post_process_args = None
-        self._concurrent = _concurrent
+        self._concurrent = _concurrent if not isinstance(_concurrent, bool) else 5 if _concurrent else 0
         self._scatter = _scatter
 
     @staticmethod
@@ -396,8 +397,10 @@ def impl(func, barrier, global_data, *args, **kw):
                 return r
 
             loop, barrier = asyncio.new_event_loop(), threading.Barrier(len(items))
-            return package(loop.run_until_complete(asyncio.gather(*[loop.run_in_executor(None, partial(
-                impl, self.invoke, barrier, lazyllm.globals._data, it, inp, **kw)) for it, inp in zip(items, inputs)])))
+            with concurrent.futures.ThreadPoolExecutor(max_workers=self._concurrent) as executor:
+                return package(loop.run_until_complete(asyncio.gather(*[loop.run_in_executor(executor, partial(
+                    impl, self.invoke, barrier, lazyllm.globals._data, it, inp, **kw))
+                    for it, inp in zip(items, inputs)])))
         else:
             return package(self.invoke(it, inp, **kw) for it, inp in zip(items, inputs))
 
@@ -420,7 +423,7 @@ def _post_process(self, output):
 #  (in1, in2, in3) -> in2 -> module21 -> ... -> module2N -> out2 -> (out1, out2, out3)
 #                  \> in3 -> module31 -> ... -> module3N -> out3 /
 class Diverter(Parallel):
-    def __init__(self, *args, _concurrent=True, auto_capture=False, **kw):
+    def __init__(self, *args, _concurrent: Union[bool, int] = True, auto_capture: bool = False, **kw):
         super().__init__(*args, _scatter=True, _concurrent=_concurrent, auto_capture=auto_capture, **kw)
 
 
@@ -430,7 +433,8 @@ def __init__(self, *args, _concurrent=True, auto_capture=False, **kw):
 # Attention: Cannot be used in async tasks, ie: training and deploy
 # TODO: add check for async tasks
 class Warp(Parallel):
-    def __init__(self, *args, _scatter=False, _concurrent=True, auto_capture=False, **kw):
+    def __init__(self, *args, _scatter: bool = False, _concurrent: Union[bool, int] = True,
+                 auto_capture: bool = False, **kw):
         super().__init__(*args, _scatter=_scatter, _concurrent=_concurrent, auto_capture=auto_capture, **kw)
         if len(self._items) > 1: self._items = [Pipeline(*self._items)]