Abstract: A hard disk duplication device capable of expanding duplication capacity by chain connection, including one or more duplicators, the duplicator including: an expansion input connection port; an expansion output connection port; an information display screen; multiple buttons including a start button and multiple selection buttons; and at least one hard disk connection port; wherein, the chain connection is achieved by connecting the expansion output connection port of one of a plurality of the duplicators with the expansion input connection port of another of the plurality of the duplicators.