This paper has summarized five surface strengthening methods, and these methods could to improve the surface properties of materials. The selection of mechanical parts materials has determined according to their working conditions. The work-piece in using cannot avoid defects in the material. This paper has introduced surface deformation enhancement, surface phase transformation enhancement, ion implantation technology, surface diffusion and infiltration technology, chemical transformation technology and surface coating technology. And has also included the principle of every surface technology, various technologies, parameters, strengthening characteristics, as well as strengthening effect and matters needing attention. The hardness, residual stress and corrosion resistance off mechanical parts could be improved through these surface strengthening methods. It is convenient to find the strengthening method and parameters in this paper when strengthening mechanical parts.