With human society entering the twenty-first Century, people have paid more and more attention to sports. And in recent Olympic Games, China athletes have got good results for the glory of the Chinese nation, and also promoted the development of sports in China. In all kinds of sports, the explosive force of the lower limb has a great impact on the competitive sports. In order to get better athletic performance, we need to adopt more scientific and reasonable training methods to improve the explosive force of the athletes’ lower limbs. With the development of science and technology, the application of computer technology in sports has been more extensive. Through the computer system, the acquisition, storage, analysis of related images, strength and other data of the athletes in the process of sports were carried on, to find out the lack of action, and the targeted training methods were put forward. In the design of the sports system which improves the explosive force of the lower limb, the design of motion picture system and the system design of three dimensional force measuring platform were completed. In this way, the collection and analysis of the motion image and the dynamic correlation data were carried out. Finally, through the test of the system, it can be seen that the system can fully analyze the data parameters of the athletes in the training action, and provide data base for the training to improve the explosive force of the lower limbs of athletes.