Method and device for virtualizing physical host system

The invention provides a method for virtualizing a physical host system. The method comprises receiving an input physical host virtualizing instruction, loading a mirror image document of a virtual machine management system after restart and guiding into the virtual machine management system, obtaining the disk of the physical host system, creating a virtual machine by use of the virtual machine management system, wherein the disk of the corresponding physical host system is used as the disk of the created virtual machine. The invention also provides a device for virtualizing the physical host system, and a method, a device and a system for migrating the physical host system to the virtual machine. The method and the device for virtualizing the physical host system, and the method, the device and the system for migrating the physical host system to the virtual machine are capable of improving the convenience of operations.