This research is aimed at the development of computer-aided polishing technology for optical surfaces using magnetorheological (MR) fluid as medium. The mechanism of a dual-axis polishing wheel and the mathematical model combined with a symmetrical tool function are demonstrated. The effects of speed, gap, time and geometric parameters of the tool have been experimentally evaluated by polishing a parabolic BK7 mirror in 120 mm diameter. The surface topography presented an obvious amelioration, and the shape accuracy decreased to 0.067l from 0.519l (l = 632.8 nm, RMS) after 75 min finishing.