Abstract: For asymmetric transmitting coil and receiving coil of magnetic coupling resonant wireless power transmission system in practical application and low system transmission efficiency, an asymmetric system model was built whose transmitting coil was larger than receiving coil. A method for improving system transmission efficiency was proposed which was by increasing repeating coil between the transmitting coil and the receiving coil. A structure was proposed, namely the repeating coil and the transmitting coil were coaxial and in the same plane. The simulation was done to compare the method with a method of increasing turn number of the transmitter coil about influence on system transmission efficiency. The simulation results show that the former can improve the transmission efficiency more efficiently with a smaller volume. Experimental platform of the system was built in laboratory to verify correctness of theoretical analysis and simulation.