A data migration method is disclosed, including: determining a first address of target data that is to be migrated from an internal storage device to an external storage device, the first address is a logical address of the internal storage device; calculating a physical address of the target data in the internal storage device based on the first address; constructing a scatter gather list, where the scatter gather list includes the physical address of the target data in the internal storage device; sending a migration instruction to a direct memory access engine.