1. A file reading method, applicable to reading of a file stored on a storage device, wherein the storage device comprises a first storage medium and a cache, wherein an access speed of the cache is greater than that of the first storage medium, wherein the first storage medium has a plurality of containers, and wherein the file comprises a plurality of file segments, the method comprising: receiving, by the storage device, a first read request sent by a client, wherein to-be-read data requested by the first read request is a part of the file; reading, from the cache, data that is of the to-be-read data and located in the cache; reading, from the first storage medium, data that is of the to-be-read data and not located in the cache; pre-reading, from the first storage medium, data in at least one of the containers; and storing the pre-read data into the cache, wherein the pre-read container comprises at least one unread file segment of the file.