diff --git a/mindinsight/profiler/analyser/step_trace_analyser.py b/mindinsight/profiler/analyser/step_trace_analyser.py
index 58ea05e8e7d48adbc0af6542bd736dd4136a4251..91b9bc21b3e0a9b9ead35e8d55d65da8e517f800 100644
--- a/mindinsight/profiler/analyser/step_trace_analyser.py
+++ b/mindinsight/profiler/analyser/step_trace_analyser.py
@@ -83,7 +83,7 @@ class StepTraceAnalyser(BaseAnalyser):
             row_info_dict = self._get_info_dict_from_row_data(row_info, 'systime')
             reduce_info = self._sort_reduce_by_time(row_info_dict)
             if reduce_info:
-                reduce_infos.append(reduce_info)
+                reduce_infos.extend(reduce_info)
 
         return reduce_infos
 
@@ -282,8 +282,9 @@ class StepTraceAnalyser(BaseAnalyser):
                 log.info("Reduce event missing value.")
                 continue
             cur_stream_id = reduce_field.split('_', 2)[1]
-            reduce_info = [reduce_field, int(cur_stream_id), reduce_start,
+            reduce_meta = [reduce_field, int(cur_stream_id), reduce_start,
                            reduce_duration, reduce_pid]
+            reduce_info.append(reduce_meta)
 
         return reduce_info
 
diff --git a/mindinsight/profiler/profiling.py b/mindinsight/profiler/profiling.py
index e52a300142566b7ac2c791f5bca82fec8b029f11..e5d841d0c7e3054803a08b5ff724f5a9212b660a 100644
--- a/mindinsight/profiler/profiling.py
+++ b/mindinsight/profiler/profiling.py
@@ -236,6 +236,12 @@ class Profiler:
     def _analyse_timeline(self, aicpu_parser, optime_parser):
         """
         Analyse and parse timeline info.
+
+        Args:
+            aicpu_parser (DataPreProcessParser): The parser instance for AI CPU operator
+                execution time calculation.
+            optime_parser (OPComputeTimeParserParser): The parser instance for AI Core
+                operator execution time calculation.
         """
         timeline_analyser = AnalyserFactory.instance().get_analyser(
             'timeline', self._output_path, self._dev_id