Disclosed are a method and device for implementing memory migration, which relate to computer technology and are invented for solving the problem that the existing operating process for memory migration is relatively complicated. The technical solution provided in the embodiments of the present application includes: the basic input-output system of a computer migrating the data in the memory to be migrated to a first unavailable memory in the operating system of the computer when migrating the memory to be migrated and the basic input-output system storing the mapping relationship between the memory to be migrated and the physical address of the first unavailable memory. The embodiments of the present application can be applied to ordinary computer systems and computer systems under the NUMA architecture.