Abstract: With the development of network and information technology, online course platforms are playing an important role. In view of the reduction of the course hours, the book knowledge is expanded in the form of the extended reading of the online course. Based on the online course platform, this paper extends the fatigue problem of metal materials under the stable alternating load to the fatigue problem of metal materials under the unstable load and the fatigue problem of non-metal materials, and the fatigue life estimation formula is introduced through examples. Using the online platform to integrate resources and expand knowledge plays an important role in cultivating students' ability to analyze and solve problems.