diff --git a/applications/main.c b/applications/main.c
index 65e4b1a..8172db4 100644
--- a/applications/main.c
+++ b/applications/main.c
@@ -170,8 +170,8 @@ int main(void)
                         && gas_calibration_voltage < (MQ_VOLTAGE_ALARM_DEFAULT + 500))
                     {
                         uint8_t calibration_buf[2] = {0};
-                        calibration_buf[0] = gas_calibration_voltage << 8;// 低字节
-                        calibration_buf[1] = gas_calibration_voltage >> 8;//高字节
+                        calibration_buf[0] = gas_calibration_voltage & 0xFF;  // 低字节
+                        calibration_buf[1] = (gas_calibration_voltage >> 8) & 0xFF;  // 高字节
                         LOG_D("calibration_buf[0] = %X calibration_buf[1] = %X", calibration_buf[0], calibration_buf[1]);
                         Flash_Sys_Cfg(kAlarmLValueId, calibration_buf, 2);
                         // 标定完成打开绿灯常亮,蜂鸣器叫一下