A lot of highly precise surfaces are needed at the semiconductor and the medical field. For removing the machining traces of plane surfaces, magnetic abrasive finishing (MAF) is an effective method in which magnetic brush that formed by magnetic particles and magnetic force. In this reseach, to achieve super-precise surface, the influence exerted on finishing characteristics was considered, and the most suitable processing conditions were considered to figure out the finishing properties of MAF, three elements are set as objects in this study, including the size of abrasive particle, the types of magnetic pole and the clearance between workpiece and pole. In this study, the three elements have been studied and their best conditions have been found. At the same time, the magnetic flux densities of magnetic poles are investigated by electromagnetic simulation. At last, a new multistep finishing has been proposed that can finish plane surface into nanometer-scale. The surface roughness has been improved from 381.32 nm Ra into 12.02 nm Ra.