The invention discloses a method and a device for live migration of a virtual machine. One specific embodiment of the method comprises the steps that when a request for live migration of the virtual machine to a destination physical machine is received, CPU information of a source physical machine and CPU information of the destination physical machine are acquired; whether a CPU instruction set architecture of the source physical machine and a CPU instruction set architecture of the destination physical machine are compatible or not is determined; when the CPU instruction set architectures are compatible, whether CPU features of the source physical machine and CPU features of the destination physical machine are compatible or not is further determined; when the CPU features are not compatible, whether the incompatible CPU features of the source physical machine and the destination physical machine are in a preset list or not is further determined; responding to the determination that the incompatible CPU features are in the preset list, the virtual machine is lively migrated to the destination physical machine from the source physical machine. According to the embodiment, dynamic migration of the virtual machine in a heterogeneous cluster is realized, the virtual machine capable of achieving dynamic migration is no longer limited to the same physical CPU model, and compatibility is achieved with as little performance sacrifice as possible.