The analysis on fatigue cracks of the outer race of aero-bearing shows that the distribution of residual tensile stress on race surface could reduce its contact fatigue life. The method of pre-stress hard machining, which is a process that imposes a tensile stress to work piece within elastic limit beforehand and then exerts machining, can actively control the residual stress states of machined surface. Based on the characteristics of pre-stress hard machining, a 3D coupled thermo-mechanical model is constructed. Several key numerical techniques, such as the constitutive equation of material, the Arbitrary Lagrangian Eulerian (ALE) method and the friction law along the chip-tool interface have been analyzed and implemented. In the end, through combining cutting experiments and numerical simulations, the residual stress states of machined surface in pre-stress hard machining are compared and analyzed. Simulation and experiment results indicate that this method can acquire residual compressive stress on machined surface and prolong the contact fatigue life.