diff --git a/df_datalink_sp/src/systembus/systembus.c b/df_datalink_sp/src/systembus/systembus.c
index 0222a36..03fb884 100644
--- a/df_datalink_sp/src/systembus/systembus.c
+++ b/df_datalink_sp/src/systembus/systembus.c
@@ -579,7 +579,7 @@ int32_t SystemBus_HandleCmd(SYSBUS *instPtr)
 		TIME_WORD tmWord;
 		uint64_t time;
 		TimeCtrl_GetCurrentTime(linkInstPtr->config.tmcInstPtr, &tmWord);
-		time = tmWord.int_part * TIME_FRAC_MAX + tmWord.frac_part;
+		time = (uint64_t)tmWord.int_part * TIME_FRAC_MAX + tmWord.frac_part;
 		memcpy(sysbusRsp->data + WD_FLJ_TIME_STAMP, &time, WD_FLJ_TIME_STAMP_LEN);
 		SysMonitor_GetLinklayerLog(&(instPtr->linkLog));
 		SysMonitor_GetPhysicalLayerLog(&(instPtr->phyLog));
@@ -622,7 +622,7 @@ int32_t SystemBus_HandleCmd(SYSBUS *instPtr)
 		TIME_WORD tmWord;
 		uint64_t time;
 		TimeCtrl_GetCurrentTime(linkInstPtr->config.tmcInstPtr, &tmWord);
-		time = tmWord.int_part * TIME_FRAC_MAX + tmWord.frac_part;
+		time = (uint64_t)tmWord.int_part * TIME_FRAC_MAX + tmWord.frac_part;
 		memcpy(sysbusRsp->data + WD_LJ_TIME_STAMP, &time, WD_LJ_TIME_STAMP_LEN);
 		SysMonitor_GetLinklayerLog(&(instPtr->linkLog));
 		SysMonitor_GetPhysicalLayerLog(&(instPtr->phyLog));