Abstract: This paper establishes a joint simulation model for the magnetically coupled resonant coil in electric vehicle wireless charging by analyzing influencing factors of coil transmission performance. According to the simulation results comparing the coupling coefficient and transmission efficiency of different circular and square coupling coils in the case of offset, it is shown that the circular coil can still guarantee about 70% transmission efficiency in the case of lateral offset of 10 cm, and its output power is much higher than that of the square coil. And the paper optimizes the structure parameters of the circular coil, adds the E-type ferrite core, and optimizes the output power of the electromagnetic coupling coil by simulation, even when the lateral offset reaches 20 cm, the output power also reaches 2 996. 4 kW, ensuring 85% of the transmission efficiency, and meeting the anti-offset performance transmission requirements of the national electric vehicle wireless charging magnetic coupling coil.