A complex high-density soybean grinder comprises a first filter unit and a second filter unit; a suction unit having a feeding tube for supplying soybeans; a lateral side of the suction unit being installed with a blower and a sound canceller so that soybean can enter into the suction unit; a feeding unit connected to the suction unit and the first filter unit; an electric controller serving to control the feeding unit; a regeneration barrel set connected to the first filter unit and the second filter unit for mixing and agitating soybean dregs from the first filter unit with water; and then the mixed dregs and water being fed into the second filter unit; a reuse barrel set connected to the first filter unit for feeding liquid from the second filter unit to the regeneration barrel set and then to the first filter unit through is pump.