Abstract: Fetal heart rate (FHR) is an important index to the fetal health evaluation. Therefore, the study of the system is of great significance to the monitoring of FHR. In this paper, the detection principle, the overall framework of the system, hardware composition, PC software interface and so on have been made a detailed implements. The display of instant heart rate, heart rate trendline, and fetal heartbeat have been achieved. A large amount of test data of this system has been got by fetal feart simulator testing in the laboratory and preliminary clinical tests in the hospital. The testing result showed that using the system can achieve good accuracy and repeatability.