Abstract: This paper analysed the problem of the location accuracy of the feed system of machine tool theoretically, derived a theoretical formula expressing the location accuracy of the feed system, and advanced some principle for the design of the precision microfeed mechanism On this basis, with the study and experiment of the precision and superprecison microfeed mechanism, the precision axial microfeed mechanism of cylindrical grinder and the super pecision elastic deformation microfeed mechanism of lathe have been developed successfully.