This paper aims to explore the problems existing in the operation process of online after-sales service, and improve the operation experience of users. According to the construction rules of HTA model and the characteristics of online after-sales service operation process, such e-commerce platform as Taobao, Tmall, JD and Pinduoduo are selected as the representatives for hierarchical task decomposition and comparative analysis. The operation process is sorted out and the hierarchical structure chart is drawn. The performance experiment is conducted by simulating the real after-sales service operation scene by programming software, and the task operation time and task operation completion rate are obtained by the USE usability scale and in-depth interview.The results show that Taobao is better than JD in terms of operation time, operation error times and usability, and the operation interface is an important factor affecting the user's operation experience. the conclusion and optimization suggestions are as follows:appropriately reducing the repetitive operation can effectively reduce the operation time and improve the operation efficiency; improving the accuracy of the information expression of the operation interface can reduce the operation error, reduce the confusion of the information displayed on the interface, thereby improving the user's operation experience.