Abstract: A method for one-to-multiple copying of data storage medium is provided, applicable to a hard disk copying system to copy the source data in a source hard disk to a plurality of target hard disks. The method includes steps of preparing a source hard disk and a plurality of target hard disks, and placing the target hard disks to hard disk receiving slots of the hard disk copying system; detecting and recording the number and addresses of the target hard disks; and copying the source data in the source hard disk to the target hard disks one by one. The method further includes steps of data compression and decompression to accelerate the data copying process.