Since the emergence of machinery, there are corresponding mechanical parts. But as a discipline, mechanical parts are separated from mechanical tectonics and mechanics. With the development of the mechanical industry, the emergence of new design theories and methods, new materials and new technologies has made mechanical parts enter a new stage of development. The theory of finite element method, fracture mechanics, elastohydrodynamic lubrication, optimal design, reliability design, computer aided design (CAD), solid modeling (Pro, Ug, Solidworks, etc.), system analysis and design methodology have been gradually applied to the research and design of mechanical parts. It is an important trend for the development of this discipline to realize the integration of various disciplines, to realize the combination of macro and micro, to explore new principles and structures, to use more dynamic design and accurate design, to use electronic computers more effectively and to further develop design theories and methods.