diff --git a/api/core/workflow/graph_engine/graph_engine.py b/api/core/workflow/graph_engine/graph_engine.py
index a05a52355c..361e2012d4 100644
--- a/api/core/workflow/graph_engine/graph_engine.py
+++ b/api/core/workflow/graph_engine/graph_engine.py
@@ -1,5 +1,6 @@
 import logging
 import queue
+import threading
 import time
 from collections.abc import Generator
 from concurrent.futures import ThreadPoolExecutor
@@ -37,7 +38,6 @@ from core.workflow.nodes.node_mapping import node_classes
 from extensions.ext_database import db
 from models.workflow import WorkflowNodeExecutionStatus, WorkflowType
 
-thread_pool = ThreadPoolExecutor(max_workers=500, thread_name_prefix="ThreadGraphParallelRun")
 logger = logging.getLogger(__name__)
 
 
@@ -217,15 +217,15 @@ class GraphEngine:
                     q: queue.Queue = queue.Queue()
 
                     # new thread
-                    futures = []
                     for edge in edge_mappings:
-                        futures.append(thread_pool.submit(
-                            self._run_parallel_node,
-                            flask_app=current_app._get_current_object(),  # type: ignore
-                            parallel_id=parallel_id,
-                            parallel_start_node_id=edge.target_node_id,
-                            q=q
-                        ))
+                        run_thread = threading.Thread(target=self._run_parallel_node, kwargs={
+                            'flask_app': current_app._get_current_object(),
+                            'parallel_id': parallel_id,
+                            'parallel_start_node_id': edge.target_node_id,
+                            'q': q
+                        })
+
+                        run_thread.start()
 
                     succeeded_count = 0
                     while True:
@@ -247,10 +247,6 @@ class GraphEngine:
                         except queue.Empty:
                             continue
 
-                    # not necessary
-                    # for future in as_completed(futures):
-                    #     future.result()
-
                     # get final node id
                     final_node_id = parallel.end_to_node_id
                     if not final_node_id: