The invention provides a corrugated board crosscut correcting device when the end moves during the replacement of the boards. A rotation shaft (1) is arranged on a pedestal (2), one end of each of a group of correcting strips (5) is connected with the rotation shaft (1) in a movable way, the cylinder body of an air cylinder (3) is fixed on the pedestal (2), a piston of the air cylinder (3) is connected with the rotation shaft (1) through a rocker arm (4). The device also has a mandrel (8) which is fixedly connected with the rotation shaft (1). One end of a group of correcting strips (5) is flexibly connected with the mandrel (8). The corrugated board crosscut correcting device has the advantages of simple structure, low cost, less production cost and easy installation and maintenance.