diff --git a/internal/client_channel.go b/internal/client_channel.go
index f71f2c2..de1f3c8 100644
--- a/internal/client_channel.go
+++ b/internal/client_channel.go
@@ -28,19 +28,32 @@ func (t *TClient) Channel(ctx context.Context, channel *tg.Channel, cfg *Channel
 	if err != nil {
 		return errors.Wrap(err, "messages.getHistory")
 	}
+	if len(messages.(*tg.MessagesChannelMessages).GetMessages()) == 0 {
+		t.logger.Info("no new message")
+		return nil
+	}
 
 	downloader := downloader.NewDownloader()
 	lo.ForEach(messages.(*tg.MessagesChannelMessages).GetMessages(), func(item tg.MessageClass, index int) {
+		defer func() {
+			t.logger.Info("update config", zap.Int("offset", cfg.Offset))
+			if err := cfg.Update(ctx, item.GetID()); err != nil {
+				t.logger.Error("update config failed", zap.Error(err))
+			}
+		}()
+
+		switch item.(type) {
+		case *tg.MessageEmpty:
+			return
+		case *tg.MessageService:
+			return
+		}
+
 		msg, ok := item.(*tg.Message)
 		if !ok {
 			t.logger.Error("convert msg to *tg.Message failed")
 			return
 		}
-		defer func() {
-			if err := cfg.Update(ctx, msg.ID); err != nil {
-				t.logger.Error("update config failed", zap.Error(err))
-			}
-		}()
 
 		channelMessage := NewChannelMessage(msg.ID)
 		defer cfg.SaveMessage(channelMessage)
diff --git a/internal/cmd_export.go b/internal/cmd_export.go
index 7ab274b..27d3f3a 100644
--- a/internal/cmd_export.go
+++ b/internal/cmd_export.go
@@ -57,5 +57,9 @@ func exportCmd(ctx context.Context) error {
 	}
 
 	// https://t.me/yunpanshare/37426
-	return client.Channel(ctx, channel, cfg, modeHistory)
+	for {
+		if err := client.Channel(ctx, channel, cfg, modeHistory); err != nil {
+			return err
+		}
+	}
 }