With the continuous improvement of the requirements for power supply quality, safety, reliability, convenience, immediacy, special occasions, and special geographical environment of electrical equipment, the contact type power transmission method is more and more unable to meet the actual needs. The wireless charger is a device that uses the principle of electromagnetic induction to charge. signal and convert the electromagnetic signal into electric current, so as to achieve the purpose of wireless charging. Wireless charging technology is a special power supply method that does not require a power cord, relies on electromagnetic wave propagation, and then converts the electromagnetic wave energy into electrical energy, and finally realizes wireless charging. New electronic products, especially portable electronic products such as digital cameras, mobile phones, tablet computers, etc., are used more and more in people's work and life, and the matching chargers also follow the traditional wired chargers. However, the compatibility and versatility of wired chargers are relatively poor, and it is inconvenient for users to carry and charge. At the same time, the post-disposal treatment increases the pollution to the environment. Therefore, it is imminent to provide users with more reliable, convenient, convenient and timely charging equipment. The development of wireless technology makes the transmission of radio power possible, and the research and development of wireless chargers will also meet the requirements of users.