File management system in small storage space

The invention discloses a file management system in a small storage space. The file management system comprises a file creating unit, a file deleting unit, a file operating unit and a file storage space managing unit, wherein the file creating unit comprises a file creation safety condition judging operation, a file space application operation, a file registration operation and a file control information writing-in operation and is used for realizing the distribution of file space against different file categories and writing-in of file control information; the file deleting unit comprises safety state judgment and file logic deletion and can realize the deletion of a file application and simultaneously retain the continuity of the file system; the file operating unit comprises file selection, data saving, data reading, data modification and a file reading and writing operation and can realize selection, saving, reading and modification of a file and control the access of the file; and the file storage space managing unit comprises file space distribution and file operation boundary management and can realize the file operation boundary control and prevent a cross-border operation during the file operation process.