The technology of wireless power transfer has made a great contribution to the quality of life of many people, especially to those relying on implantable devices in the past decades. In order to improve the performance of wireless power transfer systems, a dual-layer nested optimization method using differential evolution (DE) algorithm is proposed in this paper. In contrast to previous methods to derive the compensated capacitance, this proposed method determines the capacitance values using optimization method. By testing a prototype, it is found that the proposed design can have much higher power transfer efficiency when compared to that of traditional method. The dual-layer nested optimization method, based on the design constrains, is also used to determine the parameters of the coils to obtain the maximum power transfer efficiency of the whole system. The result is validated using finite element method (FEM).