The wet permanent magnet drum type magnetic separator mainly consists of cylinder, roller, brush roller, magnetic system, trough body and transmission part 6. The cylinder is welded by 2-3mm stainless steel plate, and the end cover is cast aluminum or workpiece. It is connected with stainless steel screw and cylinder. The motor drives the cylinder, magnetic roller and brush roller to rotate through the speed reducer or directly using the infinitely variable speed motor. The magnetic system is an open magnetic system, mounted in the cylinder and exposed to total magnetism. The magnetic block is mounted on the bottom plate of the yoke with stainless steel bolts. The shaft of the yoke extends out of the cylinder, and the crank arm is fixed on the shaft end. The deflection angle of the magnetic system can be adjusted by pulling the crank arm, and can be fixed with a pull rod after adjusting properly. The working area of the tank is made of stainless steel plate, and other parts of the rack and trough are welded by ordinary steel.