Objective To develop an applied software to describe and estimate the mechanical functions of the lower extremities muscles during movement. Methods The original data of 3D coordinates of muscle attachments of lower extremities and the methods to establish the muscular function model comes from a previous research[3]. Results The software developed in this study could output the values of function parameters of lower extremities muscles for any simulated joint angle configuration or real motions. Conclusion The data from the computer model could coach specific muscles strength training to improve athletic performance and also have a good prospect of application in the related fields of medicine.