diff --git a/app.py b/app.py
index 36f823e..c38a584 100644
--- a/app.py
+++ b/app.py
@@ -1,6 +1,7 @@
 import cv2
 import json
 import time
+import torch
 import requests
 import threading
 import numpy as np
@@ -61,6 +62,8 @@ def worker(id,source,region=None,stream=False):
         region = 10
     else:
         region = int(region)
+    device_count = torch.cuda.device_count()
+    print("GPU device count:", device_count)
     print("start loading model...",id,source,region)
     model = YOLO('./best.pt')
     print("start loaded  model!!!")
@@ -92,7 +95,7 @@ def worker(id,source,region=None,stream=False):
                             print("Error opening video stream....")
                         break
                 continue
-            result = model.track(frame,show=False,stream=False,persist=True,device=int(id)%4)
+            result = model.track(frame,show=False,stream=False,persist=True,device=int(id)%device_count)
             use += " track:"+str((time.time()*1000) - bgn)
             del(ret)
             del(frame)