Abstract: An unmarked body motion tracking system based on multi-Kinect V2 is provided and includes: Kinect V2s, configured to acquire depth data and joint data; analysis modules, configured to analyze data collection characteristics of single Kinect V2 and transmission device assembly requirements; clients, configured to receive and process data collected by Kinect V2s. A process of the data processing includes: based on the data collection characteristics of the single Kinect V2, a client-server model is built to track a human body from different directions; output modules, configured to output layout modes and tracking results of the Kinect V2s. According to the data collection characteristics of the single Kinect V2 and the transmission device assembly requirements, the disclosure minimizes the mutual interference between the opposite Kinect V2s, tracks the human body from different directions, and ensures that the joints in the self-occlusion state are stably tracked by sensors at other angles.