diff --git a/core/storymanager/rank/rank.py b/core/storymanager/rank/rank.py
index bdff16ed..a6b2ec24 100644
--- a/core/storymanager/rank/rank.py
+++ b/core/storymanager/rank/rank.py
@@ -236,6 +236,8 @@ def _draw_pictures(self, test_cases, test_results):
             out_put = test_case.output_dir
             test_result = test_results[test_case.id][0]
             matrix = test_result.get("Matrix")
+            if not matrix:
+                continue
             for key in matrix.keys():
                 draw_heatmap_picture(out_put, key, matrix[key])