Method for preventing destroying file system in abnormal power cutting off

The invention is a saving method to protect file system when the computer is abnormally cut-off. It includes at least the following steps: separate the file system memory region into first memory region and second region, make cross backup on the files in the two memory regions, and the system makes cross access on the files in the two memory regions. The system, based on double-backup theory, through cross backup and access, realizes the protection of file system.