In view of the abnormal situation that may occur overcurrent problems when the wireless charging system of electric vehicles start-up, in order to realize the normal start-up, a new start-up stage control strategy is proposed. Firstly, based on the mathematical model of LC compensation structure, this strategy analyzed the overcurrent problems of the system in the case of self-resonant frequency offset, position offset and battery equivalent change; Then, the relationship between the operating frequency of the system and the output phase angle of the inverter was deduced, and the optimal operating frequency range and initial start-up voltage of the system were obtained based on MATLAB numerical simulation, and then the PID controller of the starting process was designed. The controller not only guarantees the system to realize zero voltage switching, but also suppresses the over-current in the start-up stage. Finally, the laboratory prototype system was developed, and through charging experiments on a 72V lead-acid battery, the availability and superiority of the designed control strategy are verified.