The invention belongs to the field of building equipment and particularly discloses a crushing device. The crushing device comprises a rack, a pressing plate, a bottom plate, positioning pins and air cylinders, wherein a formwork is fixedly mounted on the ground and baffles are arranged at the periphery of the rack; the pressing plate is in sliding connection with the rack; a hydraulic cylinder is fixedly arranged above the pressing plate; the hydraulic cylinder drives the pressing plate to ascend or descend; the bottom plate is fixed on the ground, is fixedly connected with the rack, is located just below the pressing plate, and is provided with connecting holes; the positioning pins are located in the connecting holes; the positioning pins are in sliding connection with the bottom plate; a sphere-crown-shaped crown head is arranged at the upper part of each positioning pin; the air cylinders are buried below the bottom plate; each positioning pin is connected with the corresponding air cylinder; the air cylinders are respectively used for driving the positioning pins to stretch out or retract back; connecting pipes, which are communicated with one another, are arranged among all the air cylinders; the connecting pipes are provided with pressure leaking pipes. Aiming at the technical problems that small stone blocks are easily splashed to injure people and large ores are difficult to fix in a primary crushing process, the invention provides the crushing device.