The machine design and the machine building are closely related, and the relationship between the two is intertwined. In the theory, the condition of the machine building is based on the machine design. In the daily work, to make the machine building smoothly implemented, it must be carried out based on the condition of the machine design. An important part of the machine building is the machine design. In order to improve the performances of the mechanical products and to guarantee the reliability of the quality of the machines, there must be a good design before the production of the mechanical products. So, in the technological theory, the two are the models of production that complement each other and are the preconditions of each other.