Abstract: Through illustrating the designing of high-risk pregnancy maternal-fetal monitoring system based on the internet of things, this paper introduced the specific application of using wearable medical devices to provide maternal-fetal mobile medical services. With the help of big data and cloud obstetrics platform, the monitoring and warning network was further improved, the level-to-level administration of high-risk pregnancy was realized, the level of perinatal health care was enhanced and the risk of critical emergency of pregnancy decreased.