Abstract: In this article, a FAT file systems used in NAND memory improve on the reliability of method, using non-fixed storage FAT table and configuration look for bad block replacement automatically algorithm completely shielding bad block on the upper applications and thus overcome the above-mentioned obstacles.This method has overcomed above-mentioned issues and greatly enhanced the reliability and stability of file storage at the expense of write speed.The project application has proved the above-mentioned advantages, and it has very high value of promotion and application.