Abstract: The mechanical behavior of the disc-spring was analyzed. The load-deformation relation of the disc-spring considered frictional action has been inferred. Influential factors on the restitution coefficient of the disc-spring was analyzed. An idea was proposed that the restitution coefficient can be reflected with the combined stiffness of the disc-spring and their relation can be expressed by modelling of index function. Disc-spring driving cap can be arranged in various combinations, and the parameters can be obtianed. Program for optimization on pile driving, is presented and optimum combination of parameters on pile driving under a certain condition including pile, soil and hammer can be found. Example showed that by using the optimum combination of parameters obtained by the program the driving efficiency in-creased obviously and quality of the pile driving can also be ensured.