Abstract: This paper analyzes the problems existing in the application of the FAT32 file system in the embedded system，reserves FDT space to make FDT and DATA store sequentially，and prevents FDT and DATA from interpenetrating with each other. The redundant storage of incremental idle cluster numbers is realized by increasing the number of DBR sectors，and the necessary format error detection and error correction for DBR，FAT，and FDT is conducted. The real-time performance and reliability of the FAT32 file system applied to the embedded system are improved effectively.

Key words: FAT32 file system, SD card, redundancy, error correction, real-time performance, reliability