Magnetorheological Finishing (MRF) is widely regarded as an effective means of processing aspheric optical components. We developed a MRF polishing machine based on a robot arm. Compared to the traditional MRF polishing machines, our new generation machines are more flexible, cost-effective and efficient. The basic components of were introduced and the calculating angle was transformed. We processed a flat SiC mirror and the final accuracy is 0.012λ.