The invention discloses a multifunctional adapter. The multifunctional adapter comprises a male joint, a
wireless transmission circuit, a
protocol verification circuit, a discrete component switching circuit, at least one expansion female joint and at least one
audio frequency female joint; the invention further discloses an adapter
system and an adapter
coupling method. According to the multifunctional adapter, the adapter
system and the adapter
coupling method, disclosed by the invention, after the adapter and an intelligent communication terminal realize
protocol verification through the male joint and the
protocol verification circuit, the intelligent communication terminal realizes wired or
wireless data transmission and charging functions through the
wireless transmission circuit and / or the discrete component switching circuit, with the help of the expansion female joint and the
audio frequency female joint; the technical problems that an earphone cannot be used for listening to music, making a phone call or watching videos when a
cell phone is charged, and the
cell phone cannot be charged when a user listens to music and watches the videos by using the earphone are solved; a plurality of types of different expansion female joints can be expanded and a function of being compatible with charging wires with different types in the market is realized; the adapter and a background
server can also be subjected to data interaction through the intelligent communication terminal, so that upgraded operation is realized.