A steel strip stabilizing apparatus comprising: a plurality of steel strip damping means arranged on at least one side of a steel strip undergoing processing in a direction there towards so as to damp vibrations in the steel strip or to correct the shape of the steel strip; and a damping means moving unit connected to the steel strip damping means to move at least a portion of each of the steel strip damping means in a widthwise direction with regard to the steel strip corresponding to the width of the steel strip, the steel strip damping means comprises a central side damping means disposed at a traveling center of the steel strip, and at least one moving side damping means (10b, 10c) arranged on both sides of the central side damping means in a widthwise direction with regard to the steel strip and connected to the damping means moving unit, characterized in that the damping means moving unit comprises a screw bar rotatably provided to an apparatus casing in the widthwise direction with regard to the steel strip and is coupled to a moving block connected to the body part of the steel strip damping means, and at least one guide provided to the apparatus casing while passing through the body part of the steel strip damping means, wherein the screw bar is comprised of double screw bars (34a, 34b) having different screw directions with the central side damping means as a starting point, and when the screw bar rotates, the moving side damping means (10b, 10c) positioned on both sides of the central side damping means are close to or distant from each other with the same moving width, and the screw bar is alternately connected to the moving side damping means (10b, 10c) at upper and lower sides thereof, and wherein a driving motor connected to the screw bar of the damping means moving unit and equipped in the apparatus casing is connected to a device controller, and a steel strip edge sensor provided on both sides of the apparatus casing is connected to the device controller. a plurality of steel strip damping means arranged on at least one side of a steel strip undergoing processing in a direction there towards so as to damp vibrations in the steel strip or to correct the shape of the steel strip; and a damping means moving unit connected to the steel strip damping means to move at least a portion of each of the steel strip damping means in a widthwise direction with regard to the steel strip corresponding to the width of the steel strip, the steel strip damping means comprises a central side damping means disposed at a traveling center of the steel strip, and at least one moving side damping means (10b, 10c) arranged on both sides of the central side damping means in a widthwise direction with regard to the steel strip and connected to the damping means moving unit, characterized in that the damping means moving unit comprises a screw bar rotatably provided to an apparatus casing in the widthwise direction with regard to the steel strip and is coupled to a moving block connected to the body part of the steel strip damping means, and at least one guide provided to the apparatus casing while passing through the body part of the steel strip damping means, wherein the screw bar is comprised of double screw bars (34a, 34b) having different screw directions with the central side damping means as a starting point, and when the screw bar rotates, the moving side damping means (10b, 10c) positioned on both sides of the central side damping means are close to or distant from each other with the same moving width, and the screw bar is alternately connected to the moving side damping means (10b, 10c) at upper and lower sides thereof, and wherein a driving motor connected to the screw bar of the damping means moving unit and equipped in the apparatus casing is connected to a device controller, and a steel strip edge sensor provided on both sides of the apparatus casing is connected to the device controller.