Sports fatigue is an inevitable phenomenon, which plays an important role in the teaching and training of physical education. The explanation and application of some phenomena after sports fatigue have been the research focus of the relevant institutions at home and abroad. Based on this, the threedimensional force, image analysis and other methods of motion biomechanics were used to test the continuous and unlimited 30 deep jump motion for 20 test subjects. By controlling the experimental conditions before and after sports fatigue, the research and analysis were carried out in the weightlessness, buffering, stretching and flight of the four stages, the characteristics of time, force and impulse before and after fatigue were studied from the comparison of the force and time curves, it was concluded that the changes of biomechanical parameters not only significantly reduced the effect of jump training, but also increased the risk of joint and muscle damage. The study shows that the research on the fatigue jump movement based on sports biology can lay the foundation for the correct physical training, and provide a scientific basis for mining the potential of sports.