The invention discloses an electric vehicle wireless charging magnetic coupler with a mobile intermediate coil belonging to the technical field of electric vehicle charging and application thereof. The magnetic coupler comprises a No. 1 transmitting coil, a No. 2 intermediate coil and a No. 3 receiving coil. The parallel distance between No. 2 intermediate coil and No. 3 receiving coil is greaterthan the parallel distance between No. 2 intermediate coil and No. 1 transmitting coil, and the plate carrying No. 2 intermediate coil can move along the slide rail. As that energy transmission coil of the magnetic couple is shifted to different degree, Through the study of the maximum efficiency curve of the three-coil magnetic coupler, When the coupling coefficient between the intermediate coiland the receiving coil is unchanged, the efficiency of the magnetic coupler is easier to reach the maximum value, so the invention provides a novel magnetic coupler for wireless charging of an electric vehicle, which improves the anti-deviation ability of the wireless charging system.