diff --git a/component/train.go b/component/train.go
index 1388eb3..4b2f4cb 100644
--- a/component/train.go
+++ b/component/train.go
@@ -58,8 +58,10 @@ type TrainBtm struct {
 	lastTelegram *TrainBaliseTelegram
 }
 
+const SB_LEN = 16
+
 func NewTrainBtm() *TrainBtm {
-	return &TrainBtm{scannedBalises: make(chan *TrainBaliseTelegram, 16)}
+	return &TrainBtm{scannedBalises: make(chan *TrainBaliseTelegram, SB_LEN)}
 }
 
 // 应答器计数器加1，[0,255]
@@ -95,7 +97,9 @@ func (t *TrainBtm) Scanning(aboveBalise bool, telegram *TrainBaliseTelegram) {
 	}
 	//
 	if isNewTbt {
-		t.scannedBalises <- telegram
+		if len(t.scannedBalises) < SB_LEN {
+			t.scannedBalises <- telegram
+		}
 		t.baliseMessageCounterAdd1()
 	}
 	//