The grinding heat is utilized to induce martensitic phase transformation and strengthen the surface layer of alloy steel by raising surface temperature higher than austenitic temperature and cooling quickly. The surface residual stress is an important factor to evaluate the quality of surface hardening layer effectively. The experimental values of residual stress in the surface hardened layer are achieved by using X-ray diffraction method and corrosion stripping method. The numerical values of residual stress are simulated by using re-meshing and finite element method. The simulation values trend of residual stress in surface hardened layer is consistent with experimental results.