In order to improve VSR(Vibration Stress Relief) effect, finite elements method is applied to study VSR process factors. Simulation on moulding process, rough machining process and heat treatment are used to study the residual stress distribution of casting. The modal analysis is carried out to determine exciting frequency, exciting position and support position. Based on residual stress distribution, harmonic response analysis is applied to find relationship between dynamic stress and exciting force. Then the exciting force can be determined. The research results indicate that finite elements method can be used to determine VSR process parameters quickly and accurately.