Compound crusher, also known as vertical compound crusher, is a kind of crushing machine which combines the advantages of impact crushers and hammer crushers. It can be used for grinding middle hard ores such as iron ore, aluminum ore, gritstone, gypsum, blast furnace slag, coal gangue, phosphorus ore, and lump coal. Also, it can be used in the field of building materials, mining industry, metallurgy, coal and chemical industry. When the materials come to the crusher，the small part firstly crushed by hammer, secondly crushed by impact plate at high speed, the large part is so heavy for hammer to crush that it is fractioned by hammer frame and impact plate, then crushed by hammer in back until it falls down to the screen plate. Those materials whose size is below the size of the screen plate will be discharged, those materials whose size is bigger than the screen gap will be regrinded by the hammer, finally discharged from the discharging opening.