Abstract: A secure power-saving hard disk storage system and method having a plurality of storage units and a control unit connected to an external controller. The system detects and checks information of installation of each storage unit and control unit, driving program and format stored at the control end while executing installation. During storage selection, the storage unit selected to execute data access is conducted with a power source via an electronic switch of the control unit to activate data transmission connection. The activated storage unit then executes data access according to store or read command input from the control end. When the storage unit is no longer in use, the power source is switched to improve synchronous conduction, power consumption, high noise and greenhouse effect of high temperature generated thereby.