Four roller crusher is the use of four high-strength wear-resistant high extrusion pressure and shear relative rotation of the crushing roller to crush the material into the top two rollers (V-type crushing chamber )later,after the relative rotation of the intermediate two rollers the squeeze pressure,squeeze the material for the first time after rolling and biting mill (thick broken),then enter the relative rotation of the intermediate two rolls ,use the middle two rolls of the pressing force and engages a second squeeze rolling mill (fine break) after finally entering the next two rolls,again using the following two third squeeze roller mill (ultra-crushing)and after (only for four rolls three broken model) to the desired size and then broken sent by the transport equipment.