The invention provides a full-automatic hydraulic tensioning device for a concrete prestressed component and a use method of the full-automatic hydraulic tensioning device for the concrete prestressed component. The full-automatic hydraulic tensioning device for the concrete prestressed component comprises a hydraulic jack module. The full-automatic hydraulic tensioning device is characterized in that a hydraulic pump is connected to a stepping motor, the stepping motor is controlled by an automatic tensioning controller, and the hydraulic pump is driven by the stepping motor to supply hydraulic oil to a hydraulic actuator under the control of the automatic tensioning controller; a normally-open type hydraulic valve can adjust the hydraulic pressure between a standby pump and the hydraulic pump and is connected to the automatic tensioning controller, and the normally-open type hydraulic valve keeps the open state in the absence of external control signals, so that a flow channel between the standby pump and the hydraulic pump is formed; and a liquid storage device is connected to the standby pump and used for supplementing the hydraulic oil when the volume of the hydraulic oil in a hydraulic system changes.