Existing models of variant design process were mostly built at part level, and activity relationship definition was coarsely grained. Design process planning had to traverse all of the possible design activities, which resulted in low design efficiency and bad dynamic adaptation. A dynamic planning method for variant design process based on design structure matrix (DSM) was presented. Firstly, the variant design activity hierarchy model was built, including product level, feature level and parameter level. According to the hierarchy model, the product design activities can be divided into six types. The constraint relationships and their priority values between design activities at each level were defined. Then, the concept of virtual activity was proposed considering that traditional DSM cannot deal with the dynamics of design process. By packaging and decomposition operations of virtual activities, dynamic planning of the design process under complex coupling condition was achieved based on DSM. The design process planning and execution were alternated with each other. With the selection of dynamic design activities, the design process planning was adjusted continuously so as to ensure optimal execution sequence of the design activities. Finally, the method presented was applied to develop the bearing design wizard. Compared with traditional methods, the method presented was easier to adapt to dynamic design process, and it improved process planning efficiency and shortened design time.