Abstract: In order to solve the problem that the efficiency computing methods for CPT systems with different resonant coupling topological structures are different, a general method for efficiency computing of CPT systems with different resonant coupling topological structures was proposed through analyzing CPT systems with four typical resonant coupling topological structures. To raise the efficiency of CPT systems, the parameters of the resonant coupling topological structure of a current-fed CPT system were optimized through mathematical modeling to achieve a high efficiency of energy output. In addition, by taking the current-fed CPT system as an experimental model, the effectiveness of the proposed computing method and the optimization of parameters were discussed. The result shows that the maximum efficiency of the resonant coupling topological structure of the current-fed CPT system is 92%, while its theoretical optimization value is 93%.