A method for file storage and a storage device are disclosed. The method includes: receiving, by a file system, a file create request sent by an application, where the file create request includes a file storage characteristic and a file storage path; selecting, by the file system from M domains based on the file storage characteristic, a domain whose domain storage characteristic has a highest degree of conformity with the file storage characteristic as a target domain; creating, by the file system, a file in the target domain; and adding, by the file system, the file to a directory tree based on the file storage path. The method can facilitate file and directory management in a storage device.