The present invention discloses a safe data storing method. By connecting with a plurality of storage device, the computer system can store any one data into two separate storage devices simultaneously to form a relationship; when the data in one of the storage device is damaged, or the storage device is damaged, the present invention can take out the data from the other storage device which stores the corresponding data and stores the data into other storage device, to guarantee that any one of the data has usable data in two storage devices simultaneously. When reading data from the two storage devices, the present method can select one, and when one storage device storing the data is damaged, the method can read data from the other storage device. The present invention has low cost, strong data safety and strong expansibility, can increase or decrease the capacity of the storage device at will, and is applicable to the storage system formed by multi hard disks and multiserver, and has high data read rate. No recreating time is needed, when finding data damaged during the course of data reading, the present method can retrieve on line, without influence for the data reading and running.