This application provides a method for migrating a virtual machine and an apparatus. The method is applied to a source-end physical host, the source-end physical host includes a host machine operating system and a source-end virtual machine running in the host machine operating system, and the host machine operating system includes a PF driver. According to the technical solutions of this application, memory consistency, before and after a migration process, of a virtual machine configured with a pass-through device can be ensured.