A method and a system for identifying a file type. A modification interface may be provided so that a user inputs a file feature parameter, and the file feature parameter input by the user is added to a file type configuration file, then the file type configuration file is loaded to a state machine to perform file type identification. Therefore, the user can modify a file feature parameter in the original file type configuration file, and when a file feature parameter of a file of a certain type is changed or a file of a new type appears, the user can update a file feature parameter in the state machine in time to identify the changed file or the file of the new type. In this way, the user does not need to search for an identification tool on the Internet.