In this study, an innovative design of the stack-type piezoelectric ceramic actuator is provided. The specific Belleville (disc) springs are used to generate a constant pre-stress force to the PZT and operated in a special condition. The simulation of the structural behavior is constructed and analyzed in ATILA program by modifying the related parameters of the piezoelectric and the elastic materials, the stress between the Belleville springs and PZT and the output displacement are both calculated in the FEA model. The accuracy and correspondence between the simulation and the experimental result is determined subsequently in this paper. The comparison of the output displacement between the modeling results calculated by ATILA and the measurement shows that the nonlinearity can be improved under a specific condition when the most appropriate Belleville springs are selected. It means our new mechanical concept of the actuator can effectively promote the output efficiency of the actuator before the controller is added.