diff --git a/deepmd/main.py b/deepmd/main.py
index d829f11ba2..a507904fa2 100644
--- a/deepmd/main.py
+++ b/deepmd/main.py
@@ -984,6 +984,19 @@ def main(args: Optional[list[str]] = None) -> None:
     RuntimeError
         if no command was input
     """
+    try:
+        import multiprocessing
+        import sys
+
+        # Force fork multiprocessing start method (not available on Windows)
+        if sys.platform != "win32":
+            multiprocessing.set_start_method("fork", force=True)
+            logging.debug("Successfully set multiprocessing start method to 'fork'.")
+        else:
+            logging.debug("Skipping fork start method on Windows (not supported).")
+    except (RuntimeError, ValueError) as e:
+        logging.warning(f"Could not set multiprocessing start method: {e}")
+
     args = parse_args(args=args)
 
     if args.backend not in BACKEND_TABLE: