Abstract: A finite element model of 3500 kJ offshore wind power pile driving system under the condition of pile rejection is established based on LS-DYNA. The internal energy transfer and the dynamic response of each component of the pile driving system is analyzed based on the stress wave principle. The lumped parameter model is established based on Newton collision theory. The model considers the mass and stiffness of each component,which is in good agreement with the analysis results of the finite element model. Based on the lumped parameter model,the influence of the stiffness of cap,the mass ratio of cap and hammer,the stiffness of ring on the impact force is analyzed. It can be found that the main parameter that affects impact force is the stiffness of cap.