Times in the development of human progress, innovation has been the pursuit of human beings, the times change, human beings only in innovation to keep pace with the times, and now the world has a witness era development of electronic components: square coil, square coil used in the form of flat ferrite core coil wire coil, now many companies are equipped with a square coil, now, in the evaluation of its performance. The coil shape of the vehicle wireless power supply technology has two kinds of circular and square. The shape of the coil determines the magnetic circuit. Therefore, the power supply side and the shape of the electric side is not uniform, between the two coils can not be efficient through magnetic flux, round and square is not compatible with each other and have their own advantages and disadvantages. At present, the global car manufacturers are basically divided into two factions. Now the car wireless power supply technology has been used in a square coil.