The mineral slurry flows into the cell through box feeder, the mineral particle is loose under the function of water flow of feeder water pipe when they flow into the cell. Affected by magnetic field, the magnetic particle swarm together and form magnetic cluster or chain. With the magnetism of mineral slurry, the magnetic cluster or chain moves toward the magnetic pole, and is absorbed to the cylinder. Because of the polarity of magnetic pole, the revolving directions alternate constantly, and remain fixed when it is working. When the magnetic cluster and chain go round and round along with the cylinder, the mingled gangue and other non-magnetic ore fall down due to the mixing phenomena produced by alternation of magnetic poles, and it is concentrate that is absorbed to the cylinder surface. The concentrate moves to the end of magnetic system where the magnetism is weakest along with the revolving cylinder, and is discharged into concentrate tank by the current ejected by the discharging-ore pipe. The non-magnetic or weak magnetic remained are discharged along with the mineral slurry, and they are gangue.