The invention discloses a device for bending the printing plate edge of an offset press, comprising a pressure plate, a base plate, a support frame, a locking wheel, a spring, an eccentric shaft and a rotation shaft, wherein the pressure plate is parallel to the base plate and is arranged on the front end of the base plate; a through groove is arranged at the middle part of the rear end face of the pressure plate; the front end of the base plate is a stair landing which has a lower front end and a higher rear end; the support frame is fixedly connected with the left end and the right end of the base plate; one end of the rotation shaft is connected with the support frame, and the other end is in pin joint with the pressure plate; the spring is arranged in the through groove; the front endand the rear end of the spring respectively support against the rear end face of the pressure plate and the front end face of the base plate; the eccentric shaft comprises an eccentric wheel and a transmission shaft, the eccentric wheel is connected with the front end of the transmission shaft, the eccentric wheel is arranged inside the through groove, and the transmission shaft is arranged on a handle arranged outside the base plate; and the locking wheel comprises a wheel disc and a threaded rod, the wheel disc is arranged on the front end of the pressure plate, the front end of the threaded rod is fixedly connected with the wheel disc, and the threaded rod passes through the hole passage arranged on the pressure plate and is connected with the screwed hole of the base plate. The invention can accurately bend the edge of the plate, ensure the accuracy of the shape and the size of the bent plate edge, and increase the working efficiency.