Under the background of national fitness, we study the main factors that affect users' continuous use of fitness mobile software, explore the design method of APP, and optimize user use process. From the perspective of design, 302 questionnaires were distributed to analyze the intrinsic correlation among perceived entertainment, perceived ease of use, perceived usefulness, perceived value (perceived quality/performance value) and satisfaction in five areas and construct a relevant theoretical model using a structural equation modeling approach. According to the path study, it is found that the value perception and satisfaction of users are the main factors that affect users' continuous use of app, and the perceived value is also the main measure of user satisfaction. At the same time, the usefulness and interest of the software are the main considerations for users to make perception judgment, and users' perception of the ease of use, interest and usefulness of the software will affect each other. Fitness software should be practical, interesting and easy to use in interface design, content presentation and interactive settings.