A charging device, implemented by a first terminal, includes a transceiver, a voltage converter, and a power supply. The voltage converter is connected with the transceiver and the power supply, and is configured to step up a voltage output by the power supply and provide the stepped up voltage for the transceiver when the first terminal supplies power, and to step down a voltage input by the transceiver and supply the stepped down voltage to the power supply when the first terminal is charged. The transceiver is configured to send a wireless charging signal out based on the voltage stepped up by the voltage converter when the first terminal supplies power, and to receive a wireless charging signal and convert the received wireless charging signal into an input voltage to transmit the input voltage to the voltage converter when the first terminal is charged.