A method for determining virtual machine migration relates to the field of communications and can reduce a deployment cost. The method includes a client in a host machine obtains a unique identifier of a virtual machine on the host machine and an address of the host machine; and if the unique identifier of the virtual machine does not exist in a local record of the client, the client sends a packet to a server in a network in which the host machine is located, where the packet carries the unique identifier of the virtual machine and the address of the host machine, so that the server determines, according to the unique identifier of the virtual machine and the address of the host machine, whether the virtual machine is migrated; and the client adds the unique identifier of the virtual machine to the local record to update the local record.