diff --git a/Ubiquitous/RT-Thread_Fusion_XiUOS/aiit_board/xidatong-arm32/board/board.c b/Ubiquitous/RT-Thread_Fusion_XiUOS/aiit_board/xidatong-arm32/board/board.c
index 48db851df..68f13bd1e 100644
--- a/Ubiquitous/RT-Thread_Fusion_XiUOS/aiit_board/xidatong-arm32/board/board.c
+++ b/Ubiquitous/RT-Thread_Fusion_XiUOS/aiit_board/xidatong-arm32/board/board.c
@@ -1091,7 +1091,15 @@ void rt_hw_board_init()
 
 void rt_hw_us_delay(rt_uint32_t usec)
 {
-   ;
+    rt_uint32_t start, now, delta, reload, us_tick;
+    start = SysTick->VAL;
+    reload = SysTick->LOAD;
+    us_tick = SystemCoreClock / 1000000UL;
+    do {
+        now = SysTick->VAL;
+        delta = start > now ? start - now : reload + start - now;
+    } while(delta < us_tick * usec);
+
 }
 
 static int reboot(void)