Abstract: In order to analyze the influence of the displacer dynamic characteristics for Stirling refrigerator,the ther-modynamic model of the Stirling refrigerator was established and coupled with the dynamic model of the displacer.Through simulation calculation,the parameters such as the displacer flexure spring stiffness and the displacer mass were analyzed for the cooling capacity,displacer amplitude and phase angle of the system affect the relationship,The simulation results show that there is an optimal value for the flexure spring stiffness,which maximizes the cooling capacity of the whole machine,and the optimal frequency ratio is about 0.85.