For optimize design of the mechanism, the co-simulation of ADAMS and ANSYS was presented. Firstly the dynamic simulation analysis was finished by ADAMS; Secondly the load spectrums achieved from the dynamic simulation analysis were imported to ANSYS and the values of stress and strain were obtained; Lastly a rigid-flex coupling model was built by ADAMS to get a more real simulation of the mechanism dynamic performance and to improve the calculation accuracy. With the clamping institution as an example, the effectiveness of the method was demonstrated.