diff --git a/apps/iot/src/iot_watchdog.erl b/apps/iot/src/iot_watchdog.erl
index 1385a67..6aef686 100644
--- a/apps/iot/src/iot_watchdog.erl
+++ b/apps/iot/src/iot_watchdog.erl
@@ -223,7 +223,7 @@ format_warn(Subject, Users, PriKey) when is_binary(Subject), is_binary(Users) ->
         <<"nodeName">> => <<"主机监控"/utf8>>,
         <<"sysId">> => ?SYS_ID
     },
-    Sign = iot_jinzhi_signer:sign(PostParams, PriKey),
+    Sign = sign(PostParams, PriKey),
     jiffy:encode(PostParams#{<<"sign">> => Sign}, [force_utf8]).
 
 -spec do_post(Url :: string(), Body :: binary()) -> {ok, Resp :: any()} | {error, Reason :: binary()}.
@@ -296,4 +296,43 @@ format_date() ->
     {Date, Time} = calendar:now_to_local_time(os:timestamp()),
     {{Year, Month, Day}, {Hour, Minute, Second}} = {Date, Time},
     DateTime = io_lib:format("~4..0B-~2..0B-~2..0B ~2..0B:~2..0B:~2..0B", [Year, Month, Day, Hour, Minute, Second]),
-    list_to_binary(DateTime).
\ No newline at end of file
+    list_to_binary(DateTime).
+
+
+%% 数据签名
+-spec sign(M :: #{}, PrivateKey :: public_key:private_key()) -> binary().
+sign(M, PrivateKey) when is_map(M) ->
+    Json = serialize(M),
+    Hash = iolist_to_binary(io_lib:format("~64.16.0b", [binary:decode_unsigned(crypto:hash(sha256, Json))])),
+    RsaEncoded = public_key:encrypt_private(Hash, PrivateKey),
+    base64:encode(RsaEncoded).
+
+%% 简单的序列号，sign签名
+-spec serialize(M :: map()) -> JsonString :: binary().
+serialize(M) when is_map(M) ->
+    L = maps:to_list(M),
+    L1 = lists:sort(fun({K, _}, {K1, _}) -> K < K1 end, L),
+    serialize0(L1, []).
+
+serialize0([], Target) ->
+    B = iolist_to_binary(lists:join(<<$,>>, lists:reverse(Target))),
+    <<${, B/binary, $}>>;
+serialize0([{K, V}|T], Target) ->
+    V1 = if
+             is_integer(V) ->
+                 integer_to_binary(V);
+             is_float(V) ->
+                 float_to_binary(V);
+             is_binary(V) ->
+                 <<$", V/binary, $">>;
+             is_boolean(V) andalso V ->
+                 <<"true">>;
+             is_boolean(V) andalso not V ->
+                 <<"false">>;
+             is_list(V) ->
+                 Items = lists:map(fun(E) -> serialize(E) end, V),
+                 V0 = iolist_to_binary(lists:join(<<$,>>, Items)),
+                 <<$[, V0/binary, $]>>
+         end,
+    Item = <<$", K/binary, $", $:, V1/binary>>,
+    serialize0(T, [Item|Target]).
\ No newline at end of file