In order to study the distribution of the surface residual stress after hard turning wind power bearing under the small feed, based on the advanced nonlinear finite element analysis software ABAUQS, through the selection of materials processing flow stress constitutive model, the machining process of the wind power bearing was simulated and the surface residual stress of the bearing was obtained. By comparing the residual stress of simulation and the experiment in different depth and different rake angle parameters，the result shows that the simulation results are in good agreement with the experimental results, the residual compressive stress of 400~800 MPa can be obtained by hard turning, and the depth of the residual pressure is up to 0.04~0.08 mm.