Inductive power transfer (IPT) system with double-sided LCC (DLCC) compensation circuit is an efficient approach to improve the transmission distance and system performance. However, the optimization of associated large number of circuit parameters is still a challenge. In this paper, a novel parameter optimization method is proposed for a DLCC compensated IPT system to optimize the resonant circuit parameters. First, the transmission characteristics of the IPT system under the fundamental harmonic analysis method are introduced analyzed. By setting the reactive power excited by input and output voltage source as the optimization variables, a novel parameter optimization design method is proposed which can reduce the 7th-order optimization problem to a second-order issue. Based on the obtained method, the internal constraints of the system parameters are derived, and the optimization complexity is greatly simplified. Considering the effect of high-order harmonic, the optimized resonant circuit parameters are obtained. The effectiveness of the proposed method is verified by experimental results. The prototype can transfer 10-kW power through a 175-mm distance, with a DC-DC efficiency of 97%.