It aims to make a research on product design mode based on the action. By observing the process of people's standing and sitting, the function analysis is carried out, the rules of the variation of each leg in the leg are described, the multi point support is constructed, the design reference index is formed, and the product design is designed by the method of industrial design. The design and construction of the sketch, digital model and 3D printing model are completed, showing the design process and providing effective guidance for subsequent research and similar products.