The present invention relates to the technical field of composite board production, in particular to a hydraulic device for composite board production, including a bottom plate and a connecting frame, and the inner side of the bottom end of the bottom plate is fixedly connected with a limiting device, and the limiting device includes a first motor, a second A bevel gear, a second bevel gear, a first lead screw, a first slider, a fixed block, a push rod, a connecting plate, a push plate, a limit rod, a first spring and a stop plate, and the inside of the bottom end of the bottom plate is fixed A first motor is connected, and the main shaft end of the first motor is fixedly connected with a first bevel gear. The push plate, the limit rod and the stop plate, through the action of the first lead screw, the left and right push plates can clamp and fix the raw material at the same time, so as to ensure that the raw material will not be deflected during the pressing process, and at the same time, through the first spring The push plate can be slowly contacted with the raw material to prevent the push plate from causing instantaneous extrusion of the raw material.