The invention provides a network isolation method and a network isolation device. The network isolation method comprises the steps of receiving a first message by first network accessing equipment, wherein the first message is transmitted from a physical server and carries label information, the physical server comprises a plurality of service bridges, different service bridges are connected with the first network accessing equipment through a physical network adapter of the physical server, and the label information is added by the service bridge which corresponds with the first message; determining second network accessing equipment which corresponds with a destination address by the first network accessing equipment when the label information matches the destination address that corresponds with the first message; and transmitting the first message to the second network accessing equipment by the first network accessing equipment through network core equipment so that the second network accessing equipment transmits the first message to the physical server which corresponds with the destination address, wherein the first network accessing equipment and the second network accessing equipment are connected with the network core equipment. The network isolation method and the network isolation device have advantages of realizing network isolation, reducing wiring difficulty and reducing network maintenance cost.