In this paper, a novel magnetic medium assistant polishing technology and device is researched to complete the finish step of the optics. As the device working, the magnetic powder arranged with the magnetic field distribution. The magnetic powder became a flexible brush. The magnet wheel working with a high rolling velocity and the polishing liquid with abrasive is injected to contact region. The magnetic powder flexible brush is reforming with the magnetic field all the time, so the removal tool of the fabrication is invariable. The design and manufacture is finished and the device was connected to the CNC machine and experiment is completed to get the removal function, and roughness with K9 glass. The technology could be used in the practical fabrication.