In the paper,a RTC battery power monitoring circuit based on hardware and software dual protection is designed.The low voltage detection threshold is set on the hardware,and the battery voltage is compared with the threshold voltage by using the comparator to judge the power state.The working time of the RTC battery is detected and recorded on the software,and the power state is judged after comparing with the theoretical working time of the evaluated battery.On the hardware and software,as long as one of the methods reaches the low power judgment standard,that is,the RTC battery power is low and the battery needs to be replaced.The experiment results show that,the hardware and software dual protection RTC battery power monitoring circuit can effectively detect the battery status and avoid battery feed.