The magnetic segregator is mainly applied in coolant purification for grinders and other machine tools. When dirty fluid passes between permanent magnetic rollers and guide plate, impurities like iron chips are adsorbed to the outer walls of magnetic roller. With pressing of the rubber rollers, the coolant inside the impurities are squeezed out and the impurities will be removed to the collection tank by the scraper. This machine has an ideal separation effect, with simple contour, small cubic measurement, easy installation and long service life. It is an ideal supporting facility for purifying the coolants in processing by grinding.