The invention provides a perpendicularity calibration method and device of a hole-extrusion mandril based on laser measurement. The device comprises three laser measuring sensors, an mounting ring and a data-processing module, wherein the three laser measuring sensors are installed at the mounting ring in a uniform distribution mode, and the mounting ring is fixed on the bottom surface of an upper beam of a pressure machine; the data-processing module receives and calculates measurement-point distance information collected by the laser measuring sensors. By fixing the laser measuring sensors on the mounting ring, the calibration method and device guarantee that the laser measuring sensors have an equidistance from each other and are located on the same plane; by utilizing measuring functions of a plurality of laser measuring sensors, the calibration method and device avoid errors brought by naked eye observation, improve data precision, guarantee smooth conducting of hole extrusion, reduce defective rates, and improve working efficiency. Due to a small size, the calibration device can be used in smaller space and horizontal tests of a smaller plane. By using the laser measuring sensors, the calibration device can achieve the function of acquiring levelness information of a tested surface without contacting the tested surface, thereby judging whether or not the mandril is perpendicular to a pressure-machine head.