In order to solve the information interaction problem of electric vehicles during wireless charging, this paper proposes a method for simultaneous wireless power and data transfer (SWPDT) system based on ASK modulation. The method uses frequency division multiplexing technology to achieve simultaneous transfer of power and data; power and data transfer share the same coupling mechanism, and the power transfer channel is separated from the data transfer channel through the LC wave blocking network, which greatly enhances the flexibility of the system. The problem of self-transmitting and self-receiving data is solved by using single-blade double-throw switch to realize the conversion of data transfer direction. In this paper, the SWPDT topology is given, the power and data transfer model is analyzed and established, the simulation model is built by MATLAB/Simulink simulation platform, simulation results show that the system can realize the simultaneous transfer of power and data, and finally the feasibility of the method is verified by experiment.