Abstract: Introducing digital graphics and image techniques in the sports training, and developing a sport-oriented 3D human motion simulation and video analysis system offer a strong high-tech assurance for athletes' preparations for the 2008 Olympic Games. First, the background and significance of developing the system is introduced. Then the key functions of the system from the video analysis and 3D motion simulation are summarized. Finally, the problems to be solved and the solutions methods are discussed in detail, which include motion human body extraction and tracking in the video, 3D human motion simulation and so on. These problems and solutions are crucial to the realization of these functions.