diff --git a/tools/infer/predict_system.py b/tools/infer/predict_system.py
index 59ba4644d62b1711c55a2711d0495570709ee452..abeb91bc2572590770713af56732195f8a0de0de 100755
--- a/tools/infer/predict_system.py
+++ b/tools/infer/predict_system.py
@@ -115,7 +115,7 @@ def sorted_boxes(dt_boxes):
 
     for i in range(num_boxes - 1):
         for j in range(i, 0, -1):
-            if abs(_boxes[j + 1][0][1] - _boxes[j][0][1]) < 20 and \
+            if abs(_boxes[j + 1][0][1] - _boxes[j][0][1]) < 10 and \
                     (_boxes[j + 1][0][0] < _boxes[j][0][0]):
                 tmp = _boxes[j]
                 _boxes[j] = _boxes[j + 1]