Abstract: In order to improve the working frequency range of wireless power transfer system and quantificational design parameters of resonator, based on the theory of magnetic resonant coupling, the circuit model equation has been established. The relationship between the transmission characteristics and coil parameters has been studied. In the case of specifying resonant frequency, transmission distance, load and receiving power, the method of selecting the winding radius and turn number has been realized. At the same time, when the resonator parameters are given, the variation characteristics of transmission characteristics with transmission distance has been simulated. Finally, combined with the resonator design of broadband power converter for magnetic coupling resonance wireless energy transfer system, the theoretical deduction and simulation calculation have been validated by the experimental analysis, the results show that experimental result is consistent with theoretical analysis and simulation.