Method and system for synchronizing configuration information of power line communication PLC local area network

The invention discloses a method and a system for synchronizing configuration information of a power line communication PLC local area network. The method comprises the following steps of periodically sending a query message in a multicast form through expander equipment to determine whether a gateway device is connected; determining that a PLC link between the expander equipment and the gateway device is connected if receiving a response message returned by the gateway device within a preset time; and executing a synchronized operation of the configuration information when the expander equipment queries that the response message returned by the gateway device is not received in the last period. According to the method and the system, when the PLC link between the expander equipment and the gateway device is disconnected in any period, whether the configuration information of the gateway device is changed, the PLC link can be connected in the next period, so that the configuration information of the expander equipment and the configuration information of the gateway device are synchronized, and the reliability and the stability for a user to surf the Internet are guaranteed.