With the development of technology, there is an increasing demand for wireless charging. Among them, the magnetic resonance wireless energy transfer technology is developing particularly rapidly because of its high transmission efficiency. However, the impedance matching between devices in a wireless energy transfer system determines the efficiency of the transfer. A good impedance match plays a decisive role in improving the transmission efficiency. In this paper, we use a vector network analyzer to observe the return loss values of devices, design matching circuits and perform impedance matching adjustment.