Provided is a plug-and-play wireless network extension station and its automatic configuration process. This wireless network extension station particularly explores any wireless network extension controller over a power-line network through a power-line communication technology. The process includes broadcasting exploration packet, determining the controller's network address from a response, automatically receiving wireless network configuration and establishing a connection after self-configuration. In one embodiment, the wireless network extension station at least includes a data processing unit, a wireless-network module for providing a wireless network access service and a power-line network bridging module for data transmission using the power-line communication technology. A station exploration communication module is also provided for exploring the controller's network address via broadcast and receiving wireless network configuration. The automatic connection and network configuration achieves the plug-and-play network extension.