diff --git a/paddlehub/commands/tmpl/x_model.tmpl b/paddlehub/commands/tmpl/x_model.tmpl
index 26fae122a55430e1f6fb05d177f13a9880a5ef03..4d63a6f8c5d69b4d3b65a46d89f1238755dcb987 100644
--- a/paddlehub/commands/tmpl/x_model.tmpl
+++ b/paddlehub/commands/tmpl/x_model.tmpl
@@ -20,9 +20,9 @@ def base64_to_cv2(b64str):
 
 
 def cv2_to_base64(image):
-    return base64.b64encode(image)
-    # data = cv2.imencode('.jpg', image)[1]
-    # return base64.b64encode(data.tostring()).decode('utf8')
+    # return base64.b64encode(image)
+    data = cv2.imencode('.jpg', image)[1]
+    return base64.b64encode(data.tostring()).decode('utf8')
 
 
 def read_images(paths):
diff --git a/paddlehub/serving/app_single.py b/paddlehub/serving/app_single.py
index 10c3ea047af8faf24e974c5a77f1a4b71558da5f..fb2ce403e12938a64e99b6bbbbd2bdf152c701c1 100644
--- a/paddlehub/serving/app_single.py
+++ b/paddlehub/serving/app_single.py
@@ -17,6 +17,7 @@ from paddlehub.serving.model_service.base_model_service import nlp_module_info
 from paddlehub.serving.model_service.base_model_service import v2_module_info
 from paddlehub.common import utils
 import functools
+import traceback
 import time
 import os
 import base64
@@ -40,8 +41,7 @@ def predict_v2_advanced(module_info, input):
     try:
         output = serving_method(**predict_args)
     except Exception as err:
-        curr = time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(time.time()))
-        print(curr, " - ", err)
+        traceback.print_exc()
         return gen_result("-1", "Please check data format!", "")
     return gen_result("0", "", output)
 
@@ -66,8 +66,7 @@ def predict_nlp(module_info, input_text, req_id, extra=None):
     try:
         res = predict_method(**predict_args)
     except Exception as err:
-        curr = time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(time.time()))
-        print(curr, " - ", err)
+        traceback.print_exc()
         return gen_result("-1", "Please check data format!", "")
     finally:
         user_dict = extra.get("user_dict", [])