Abstract: In order to meet the requirements of high-speed elevators, a mathematic model of straightening process for elevator guide rails was built on the basis of elastoplastie mechanics. The relationship between deflection and bending moment and the relationship between curvature and the neutral layer were presented and can be used to calculate the deflection of straightening process. With the theoretical support, finite element software ANSYS was used to verify the rationality of the solutions and satisfactory results were obtained.