diff --git a/build/build_time_cost_test.py b/build/build_time_cost_test.py
index 4454d0a..ddd2afd 100755
--- a/build/build_time_cost_test.py
+++ b/build/build_time_cost_test.py
@@ -5,12 +5,19 @@
 import os
 import sys
 import time
+import shutil
 
 if __name__ == "__main__":
     time_start=time.time()
-    cmd=f"{' '.join(sys.argv[1:])} > build_log.log"
+    if(len(sys.argv)>2):
+        cmd=f"{' '.join(sys.argv[1:])} > build_log.log"
+        os.system("python3 ../clear_output.py > /dev/null")
+        path="../tools/gen_img/customer"
+        if os.path.exists(path):
+            shutil.rmtree(path)
+    else:
+        cmd=' '.join(sys.argv[1:])
     print(cmd)
-    os.system("python3 ../clear_output.py")
     os.system(cmd)
     time_end=time.time()
     print(f"build end, cost {time_end-time_start} s")