diff --git a/debug/accuracy_tools/api_accuracy_checker/compare/algorithm.py b/debug/accuracy_tools/api_accuracy_checker/compare/algorithm.py
index 17243a7415881198c1841afa119cc242292bfdc1..73178f463fa9dbaaa70da46b31bd4607a900ef98 100644
--- a/debug/accuracy_tools/api_accuracy_checker/compare/algorithm.py
+++ b/debug/accuracy_tools/api_accuracy_checker/compare/algorithm.py
@@ -45,8 +45,8 @@ def cosine_standard(compare_result):
 
 
 def cosine_sim(cpu_output, npu_output):
-    n_value = npu_output.cpu().detach().numpy().reshape(-1)
-    b_value = cpu_output.detach().numpy().reshape(-1)
+    n_value = npu_output.cpu().detach().numpy().flatten()
+    b_value = cpu_output.detach().numpy().flatten()
     cos = CompareConst.NA
     np.seterr(divide="ignore", invalid="ignore")
     if len(n_value) == 1:
@@ -54,15 +54,12 @@ def cosine_sim(cpu_output, npu_output):
         return get_max_rel_err(n_value, b_value)
     if n_value.dtype == np.uint8:
         return compare_uint8_data(n_value, b_value)
-    n_max = np.max(np.abs(n_value))
-    b_max = np.max(np.abs(b_value))
+    n_max, b_max = np.max(np.abs(n_value)), np.max(np.abs(b_value))
     if n_max <= np.finfo(float).eps and b_max <= np.finfo(float).eps:
         return cos, True
-    elif n_max <= np.finfo(float).eps:
-        print_warn_log("All the data is Zero in npu dump data. Compare by relative error.")
+    elif n_max <= np.finfo(float).eps or b_max <= np.finfo(float).eps:
+        print_warn_log("All the data is Zero in either npu dump data or bench dump data. Compare by relative error.")
         return get_max_rel_err(n_value, b_value)
-    elif b_max <= np.finfo(float).eps:
-        print_warn_log("All the data is Zero in bench dump data. Compare by relative error.")
     else:
         n_value = n_value.astype(float) / n_max
         b_value = b_value.astype(float) / b_max
diff --git a/debug/accuracy_tools/api_accuracy_checker/dump/dump_scope.py b/debug/accuracy_tools/api_accuracy_checker/dump/dump_scope.py
index 51dbd75d9c87ff42d6730c51af017cf6b6e03fe8..db37c4e4ce034c2b2752a9bdbfdada7d45357e35 100644
--- a/debug/accuracy_tools/api_accuracy_checker/dump/dump_scope.py
+++ b/debug/accuracy_tools/api_accuracy_checker/dump/dump_scope.py
@@ -1 +1,6 @@
-# dump范围控制 ———— 李天
\ No newline at end of file
+# dump范围控制 ———— 李天
+import torch
+from api_accuracy_checker.dump.utils import iter_tracer
+from torch.utils.data import Dataset, DataLoader
+from torch.utils.data.dataloader import _BaseDataLoaderIter
+_BaseDataLoaderIter.__next__ = iter_tracer(torch.utils.data.dataloader._BaseDataLoaderIter.__next__)
diff --git a/debug/accuracy_tools/api_accuracy_checker/dump/utils.py b/debug/accuracy_tools/api_accuracy_checker/dump/utils.py
index 93af6f0981aa0bd3d3c42606a50f04b79bc1c37b..db4417f088af760ab85d3349b32a7e998006f356 100644
--- a/debug/accuracy_tools/api_accuracy_checker/dump/utils.py
+++ b/debug/accuracy_tools/api_accuracy_checker/dump/utils.py
@@ -13,3 +13,37 @@ def write_npy(file_path, tensor):
     np.save(file_path, tensor)
     full_path = os.path.abspath(file_path)
     return full_path
+
+def set_dump_switch(switch):
+    DumpUtil.set_dump_switch(switch)
+
+class DumpUtil(object):
+    dump_switch = None
+    target_iter_range = 1
+    call_num = 0
+
+    @staticmethod
+    def set_dump_switch(switch):
+        DumpUtil.dump_switch = switch
+
+    @staticmethod
+    def get_dump_switch():
+        return DumpUtil.dump_switch == "ON"
+    
+    @staticmethod
+    def incr_iter_num_maybe_exit():
+        if DumpUtil.call_num == DumpUtil.target_iter_range :
+            DumpUtil.dump_switch = "ON"
+        elif DumpUtil.call_num > DumpUtil.target_iter_range:
+            raise Exception("Model pretest: exit after iteration {}".format(DumpUtil.target_iter_range))
+        else:
+            DumpUtil.dump_switch = "OFF"
+        DumpUtil.call_num += 1
+
+def iter_tracer(func):
+    def func_wrapper(*args, **kwargs):
+        DumpUtil.dump_switch = "OFF "
+        result = func(*args, **kwargs)
+        DumpUtil.incr_iter_num_maybe_exit()
+        return result
+    return func_wrapper