Beam of steel plate straightener

The invention relates to a beam of a steel plate straightener, and belongs to the technical field of steel strip straighteners. The beam is characterized in that the upper surfaces of the left end and the right end of an upper beam are fixedly and integrally connected with a left support and a right support respectively in a welding manner, a sensor and a hydraulic cylinder are mounted between the left support and the right support, the sensor is electrically connected with a tension PID (proportion integration differentiation) controller, the hydraulic cylinder is controlled by the tension PID controller, and the bottom end of the hydraulic cylinder and the top end of a piston rod are hinged to the left support and the right support respectively. The structure of a lower beam is as same as that of the upper beam, and the mounting direction of the lower beam is opposite to that of the upper beam. The beam has the advantages that flexible deformation of the upper beam and the lower beam in loading can be eliminated, and bounce in change of working load can also be eliminated.