An automatic calibration device for transverse shift during steel plate transportation process comprises a point light source, a convex lens, a photosensitive sensor, a main body framework, a controller, a driving device, a reducing motor, a lead screw, a lead screw nut, a right side baffle plate, a matrix reflective prismy, a left side baffle plate, and a spectroscope, wherein the point light source is fixedly mounted on the left side of the main body framework, and positioned at the focus point position on the left side of the first convex lens, the spectroscope forms an angle of 45 degrees with the ground and is fixedly mounted on the main body framework, the second convex lens is horizontally arranged above the spectroscope, the photosensitive sensor is mounted in the focus point position above the second convex lens, and the matrix reflective prismy is mounted in a position under the spectroscope; the photosensitive sensor and the driving device are both connected with the controller, the lead screw is mounted on the main body framework, and the lead screw nut is connected with the lead screw in a matched manner. The automatic calibration device provided by the invention has the following advantages: the automatic calibration device adopts a non-contact measuring way, is simple in principle and structure, is suitable for fields of different steel plate transportation, and can be used for adjusting steel plate shift positions in time and avoids dangerous accidents.