A virtual machine (VM) migration device can migrate a VM from a source location to a target location along a migration path calculated to not exceed a predetermined time limit. The migration device includes a first obtaining module, a second obtaining module, a calculation module, and a migration module. The first obtaining module obtains VM migration information and the second obtaining module obtains network status information. The calculation module calculates a migration path according to the network status information and the migration information, taking account of transmission and other delays between intermediate nodes along possible paths. The migration module migrates the VM from the source location to the target location according to the calculated migration path. A VM migration method is also provided.