The separator working principle: In the separation area of the separation cylinder, the centrifugal force and gravitation of magnetic minerals mingled with non-magnetic minerals are much less than the magnetic force. With the adsorption of the magnetic force and the joint action of the magnetic turn and agitation of magnetic minerals, the magnetic minerals will move to the inter layer gradually. When the magnetic minerals rotate to the ore unloading area with the separation cylinder, as the rotation magnetic system is eccentric, the magnetic density of the ore unloading area for the separation cylinder is extremely weak, and most of the magnetic minerals can fall off automatically. A small quantity of magnetic minerals not falling off will be adsorbed to the external surface of the ore unloading cylinder with higher magnetic density when rotating to the position nearby the ore unloading cylinder so as to realize the automatic unloading of magnetic minerals.