diff --git a/paddle/fluid/operators/detection/mine_hard_examples_op.cc b/paddle/fluid/operators/detection/mine_hard_examples_op.cc
index d4a09bae3a98e4518f9885c1e9182f7033a0d262..54a4b87ec8f13c4d474aad4cc0b8159cd5f59d1c 100644
--- a/paddle/fluid/operators/detection/mine_hard_examples_op.cc
+++ b/paddle/fluid/operators/detection/mine_hard_examples_op.cc
@@ -227,6 +227,9 @@ class MineHardExamplesOp : public framework::OperatorWithKernel {
       PADDLE_ENFORCE_GT(
           neg_pos_ratio, 0.0f,
           "neg_pos_ratio must greater than zero in max_negative mode");
+      PADDLE_ENFORCE_LT(
+          neg_dist_threshold, 1.0f,
+          "neg_dist_threshold must less than one in max_negative mode");
       PADDLE_ENFORCE_GT(
           neg_dist_threshold, 0.0f,
           "neg_dist_threshold must greater than zero in max_negative mode");
diff --git a/python/paddle/fluid/layers/detection.py b/python/paddle/fluid/layers/detection.py
index 9fae96d9bc7f5e6e89f8ee3894d28ae306e10ca9..fe1155b2930d3ce5a062a2d5a92e356e73686c8a 100644
--- a/python/paddle/fluid/layers/detection.py
+++ b/python/paddle/fluid/layers/detection.py
@@ -722,7 +722,7 @@ def ssd_loss(location,
         },
         attrs={
             'neg_pos_ratio': neg_pos_ratio,
-            'neg_dist_threshold': neg_pos_ratio,
+            'neg_dist_threshold': neg_overlap,
             'mining_type': mining_type,
             'sample_size': sample_size,
         })