An automatic switching method, comprising: - monitoring, by an automatic switching device, a service state of an operation server; and - switching, by a backup server, a current configuration of the backup server to a preset first configuration, and providing service for a client terminal, wherein the preset first configuration is a configuration of the operation server when the operation server provided service; - said monitoring is made in real time; - when the automatic switching device monitors that the operation server has terminated providing the service for the client terminal, sending, by the automatic switching device, to the operation server a switching instruction for switching a current configuration of the operation server and sending to the backup server a notification message for switching the current configuration of the backup server; - the backup server switches said current configuration to said preset first configuration according to said notification message characterized in that - before or after the step of switching the current configuration of the backup server, and after receiving a notification from the automatic switching device, switching (2032a, 501), by a network device connected to the operation server and to the backup server, a current configuration of the network device to a preset third configuration regarding division of virtual local area network VLAN, so that the backup server and the client terminal are in a same VLAN and the operation server is in another VLAN, and establishing a data communication link between the backup server and the client terminal, to enable the backup server to perform data communication with and provide service for the client terminal through the network device. - monitoring, by an automatic switching device, a service state of an operation server; and - switching, by a backup server, a current configuration of the backup server to a preset first configuration, and providing service for a client terminal, wherein the preset first configuration is a configuration of the operation server when the operation server provided service; - said monitoring is made in real time; - when the automatic switching device monitors that the operation server has terminated providing the service for the client terminal, sending, by the automatic switching device, to the operation server a switching instruction for switching a current configuration of the operation server and sending to the backup server a notification message for switching the current configuration of the backup server; - the backup server switches said current configuration to said preset first configuration according to said notification message - before or after the step of switching the current configuration of the backup server, and after receiving a notification from the automatic switching device, switching (2032a, 501), by a network device connected to the operation server and to the backup server, a current configuration of the network device to a preset third configuration regarding division of virtual local area network VLAN, so that the backup server and the client terminal are in a same VLAN and the operation server is in another VLAN, and establishing a data communication link between the backup server and the client terminal, to enable the backup server to perform data communication with and provide service for the client terminal through the network device.