The invention provides a port extension method and apparatus. According to the port extension method and apparatus, an OVS port used for accessing a VM and extended from vSwitch as a PEX device and a logic port, bound with the OVS port, on a CB device can be flexibly and effectively configured and managed along with state changes, such as network connection, network disconnection, migration and the like, of the VM in the field of virtualization, so that the network demands of the VM in various conditions are met.