diff --git a/src/bus_io.c b/src/bus_io.c
index e46aa08..364c1f2 100644
--- a/src/bus_io.c
+++ b/src/bus_io.c
@@ -151,12 +151,13 @@ void PrintState(char *str)
 {
     memset(str, 0, 150);
 
-    int count;
+    int count, flag=1;  //flag用于标记，为使下面第一个循环能够进入
     rail_node_t *p = NULL;
     char target[20], clockwise[20], counterclockwise[20];
 
-    for (count = 0, p = rails; p != NULL; p = p->next_node, count++)
+    for (count = 0, p = rails; flag==1 || p != NULL; p = p->next_node, count++)
     {
+        flag=0;
         target[count] = '0';
         clockwise[count] = '0';
         counterclockwise[count] = '0';