diff --git a/apps/iot/src/iot_logger.erl b/apps/iot/src/iot_logger.erl
index 9ffda21..aff5c04 100644
--- a/apps/iot/src/iot_logger.erl
+++ b/apps/iot/src/iot_logger.erl
@@ -138,15 +138,7 @@ flush(State = #state{file = OldFile, file_name = FileName, date = Date, buffer =
             ok = file:write(File, Content),
 
             %% 清理历史的文件, 日志文件保留一个月的
-            OldFiles = list_old_files(FileName, 30),
-            [begin
-                 case filelib:is_file(FilePath) of
-                     true ->
-                         file:delete(FilePath);
-                     false ->
-                         ok
-                 end
-             end || FilePath <- OldFiles],
+            delete_old_files(FileName, 30),
 
             State#state{file = File, buffer = [], date = get_date()};
         false ->
@@ -194,11 +186,17 @@ maybe_new_file({Y, M, D}) ->
     {{Y0, M0, D0}, _} = calendar:local_time(),
     not (Y =:= Y0 andalso M =:= M0 andalso D =:= D0).
 
--spec list_old_files(LogFile :: string(), Days :: integer()) -> [string()].
-list_old_files(LogFile, Days) when is_list(LogFile), is_integer(Days) ->
+-spec delete_old_files(FileName :: string(), Days :: integer()) -> no_return().
+delete_old_files(FileName, Days) when is_list(FileName), is_integer(Days) ->
     Seconds0 = calendar:datetime_to_gregorian_seconds(calendar:local_time()),
     Seconds = Seconds0 - Days * 86400,
-    lists:map(fun(Day) ->
+    lists:foreach(fun(Day) ->
         {Date, _} = calendar:gregorian_seconds_to_datetime(Seconds - Day * 86400),
-        make_file(LogFile, Date)
-              end, lists:seq(1, 10)).
\ No newline at end of file
+        FilePath = make_file(FileName, Date),
+        case filelib:is_file(FilePath) of
+            true ->
+                file:delete(FilePath);
+            false ->
+                ok
+        end
+                  end, lists:seq(1, 10)).
\ No newline at end of file