The present invention provides a virtual cluster establishment method and a network device. The method includes: a first network device establishes, a network-layer-based first communication connection with a second network device; the first network device sends a first registration request message to the second network device through the first communication connection, where the first registration request message is used to establish a virtual cluster with the second network device; after the first network device receives a registration response message, selecting the second network device as an active main control device in the virtual cluster system; establishes, a network-layer-based second communication connection with a third network device; sends, a second registration request message to the third network device; and selects the third network device as a standby main control device. In this invention, a structure of a cluster is simplified, and scalability of the cluster is improved.