Abstract: There is a mine founded in 1969, and the ore-dressing measure of the mine is the single magnetic-separation. In the last 40 years, 104 wet-dressing permanent magnetic tubby separators with the specification of 750×1800mm are being used. With the deep-exploitation potentiality of the mine-dressing system improved, putting the projects of boosting the utilization rate into practice, lowering the grade of tailings, and improving the metal reclaiming rate are the principal matters for ore-dressing plants. However, not only the magnetic field strength but also the magnetic structure of the old magnetic separators can hardly achieve the better results. Thus, exploring and applying new magnetic separators to lower the grade of tailings and to improve the metal reclaiming rate becomes the key problem to tackle. Through inspecting, a number of magnetic separators are compared; the compared indexes are the work structure, the magnetic structure, and the separation results. The mine accords with a new material technology research institute to test a new magnetic separator in a mine's old main plant. The separation results of the new magnetic separator are certified great through the test, and the test provides technical support for the follow-up large-scale transformation.