Novel pressure maintaining type pre-pressing clamp

The utility model relates to the technical field of clamps, in particular to a novel pressure maintaining type pre-pressing clamp. The device comprises a base plate and a protection device, hydraulic devices are fixedly connected to the four corners of the upper surface of the base plate, jacking columns are fixedly connected to the positions, close to the hydraulic devices, of the upper surface of the base plate, the protection device is arranged on the surfaces of the hydraulic devices and comprises a containing frame, the containing frame is located on the surfaces of the hydraulic devices, and sliding blocks are slidably connected to the inner walls of the two sides of the containing frame; a connecting frame is fixedly connected to the outer surfaces of the two sliding blocks, a soft cushion is fixedly connected to the side wall of the connecting frame, moving devices are arranged at the four corners of the upper surface of the base plate and comprise placing blocks, the bottom ends of the placing blocks