The magnetic separator consists of the following parts: reducer, box, magnetic roller, rubber roller and scraper. The reducer drives the magnetic roller to rotate. After the cooling liquid containing the powdery magnetic chips enters the tank, the impurities are adsorbed onto the outer wall of the magnetic roller, and then rolled by the rubber roller to extrude the liquid entrained by the impurities, and finally the scraper will be impurities. Separated from the magnetic roller.