The invention discloses an electric tightening and loosening device for a tailstock of a digital wiring unit and a method. The device is mainly included and comprises a clamping mechanism and a rotating driving mechanism; the clamping mechanism comprises a chuck; multiple rubber wheel rotating shafts are evenly distributed on and surround the chuck; rubber wheels are mounted in positions, extending out of the chuck, of front ends of the rubber wheel rotating shafts; back ends of the rubber wheel rotating shafts are connected with shaft sleeves rotationally arranged on an end cover; the rotating driving mechanism comprises a motor; an output shaft of the motor is connected with a gear transmission mechanism; and an output shaft of the gear transmission mechanism is connected with the shaft sleeves. With the device, the rotating shafts and the rubber wheels are driven by the motor to rotate, and the tailstock of the digital wiring unit is tightened and dismounted rapidly under the effect of the clamping force of the chuck.