Purpose/Significance To construct a human body model, bind it with actual human motion data, and achieve monitoring of human motion postures.Method/Process The paper designs a motion monitoring system based on Unity3D and MEMS inertial sensors. It utilizes MEMS inertial sensors to obtain human motion posture data, uses Euler angles for posture calculation, and sends the data to the computer system via the Bluetooth wireless transmission protocol to drive the movement of a virtual animated character, thereby achieving real-time 3D posture presentation of human actions.Result/Conclusion After experimental testing, the model can accurately monitor and simulate human motion postures. In the future, it can provide effective data analysis for application areas such as sports training and limb rehabilitation training.