A power adaptor includes a power input interface, a communication protocol chip, a voltage conversion chip and a power output interface; a first detection terminal of the communication protocol chip is connected to the power input interface, a second detection terminal of the communication protocol chip is connected to the power output interface, a control terminal of the communication protocol chip is connected to the voltage conversion chip; and an input terminal of the voltage conversion chip is connected to the power input interface, and an output terminal of the voltage conversion chip is connected to the power output interface.