Embodiments of the present invention disclose a power adapter. One end of the power adapter is configured to connect to a power supply apparatus, and the other end of the power adapter is configured to connect to a network terminal device. The power adapter includes a power module, a communication module, and a connection module. The power module is connected to both the communication module and the connection module, and is configured to obtain electric energy from the power supply apparatus, and supply power to the communication module and the connection module. The communication module is connected to the connection module, and is configured to communicate with the network terminal device by using the connection module. The connection module is configured to connect to the network terminal device, and transmit a signal between the communication module and the network terminal device.