The invention discloses a physical activity monitoring device. The device comprises a camera, a vital sign collection module, a motion state collection module, a human-machine operation module, a center processor, a three-dimensional effect generation module, a capacity evaluation module, a body state evaluation module, a voice module, a virtual sensor, a virtual actuator and a timing module. According to the device, the body and motion situations of an athlete are detected by different sensors with compass modules, and the detected data is subjected to analogue simulation by a three-dimensional model, so that the detector can comprehensively and accurately carry out detection, data analysis and evaluation on the motion process; the device has capacity and body state evaluating functions in the whole detecting process, so that overstrain motion of athletes can be avoided, and the detection data can be intuitive; and, due to due to the design of the voice module, all detected data can be played in a voice mode, play review can be selected according to requirement, and use of users can be greatly facilitated.