diff --git a/apps/iot/src/http_handlers/host_handler.erl b/apps/iot/src/http_handlers/host_handler.erl
index 3013a1e..5c67102 100644
--- a/apps/iot/src/http_handlers/host_handler.erl
+++ b/apps/iot/src/http_handlers/host_handler.erl
@@ -44,12 +44,11 @@ handle_request("GET", "/host/status", #{<<"uuid">> := UUID}, _) when is_binary(U
 
 %% 删除对应的主机信息
 handle_request("POST", "/host/delete", _, #{<<"uuid">> := UUID}) when is_binary(UUID) ->
-    case iot_host_sup:delete_host(UUID) of
-        ok ->
-            lager:debug("[host_handler] will delete host uuid: ~p", [UUID]),
+    case iot_host:get_pid(UUID) of
+        Pid when is_pid(Pid) ->
+            ok = iot_host_sup:delete_host(UUID),
             {ok, 200, iot_util:json_data(<<"success">>)};
-        {error, Reason} ->
-            lager:debug("[host_handler] delete host uuid: ~p, get error is: ~p", [UUID, Reason]),
+        undefined ->
             {ok, 200, iot_util:json_error(404, <<"error">>)}
     end;
 
diff --git a/apps/iot/src/iot_host_sup.erl b/apps/iot/src/iot_host_sup.erl
index 16f8b4e..9b12b06 100644
--- a/apps/iot/src/iot_host_sup.erl
+++ b/apps/iot/src/iot_host_sup.erl
@@ -37,13 +37,7 @@ ensured_host_started(UUID) when is_binary(UUID) ->
 
 delete_host(UUID) ->
     Id = iot_host:get_name(UUID),
-    case supervisor:terminate_child(?MODULE, Id) of
-        {error, running} ->
-            iot_host:kill(UUID),
-            ok;
-        _ ->
-            ok
-    end,
+    ok = supervisor:terminate_child(?MODULE, Id),
     case supervisor:delete_child(?MODULE, Id) of
         {error, running} ->
             %% ensure killed then delete again
diff --git a/apps/iot/src/message/message_codec.erl b/apps/iot/src/message/message_codec.erl
index c4c6cc9..769c11e 100644
--- a/apps/iot/src/message/message_codec.erl
+++ b/apps/iot/src/message/message_codec.erl
@@ -113,7 +113,7 @@ decode0(_, _) ->
 %%% helper methods
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
--spec marshal(Type :: integer(), Field :: any()) -> binary().
+-spec marshal(Type :: ?I8 | ?I16 | ?I32 | ?Bytes, Field :: integer() | binary()) -> binary().
 marshal(?I8, Field) when is_integer(Field) ->
     <<?I8, Field:8>>;
 marshal(?I16, Field) when is_integer(Field) ->