The invention relates to a method for designing resonance parameters of a resonant converter for an electrodeless lamp. The high-frequency LCCL resonant converter is composed of a half-bridge inverter circuit, a series-parallel resonant loop and a coupling coil, wherein the half-bridge inverter circuit is composed of a switch tube Q1 and a switch tube Q2, the series-parallel resonant loop is composed of a resonant inductor Lr, a resonant capacitor Cr, a blocking capacitor Cb and an excitation inductor Lc, and the coupling coil is composed of the excitation inductor Lc and an electrodeless lamp tube plasma discharging ring. After values of the Cb and the Lc are determined, the resonant parameters Lr and Cr are determined through a formula. In the formula, Leq and Req express an equivalent inductor and an equivalent resistor of the coupling ring auxiliary edge lamp tube plasma discharging ring mapped to the original edge, f expresses the work frequency of the resonant converter, and fo expresses the natural resonance frequency of the resonant loop. According to the method, it can be guaranteed that when the natural resonance frequency of the circuit is changed, ZVS soft switching of the electrodeless lamp can be still achieved, and the maximum power is output.