Glass material has many fine chemical properties and is widely used in hi-tech fields such as aerospace and biomedical.But its also a typical hard processing material since its brittle and very hard.Micro milling with high efficiency and flexibility, has been used more and more widely in brittle materials processing.This paper adopted this method in glass processing, and theoretically analyzed the mechanism of brittle-ductile transition of glass material during micro milling, and got the critical cutting depth of brittle-ductile transition.This paper adopt Regression orthogonal rotating combination design method to design experiments and studied the effects of milling parameters on the brittle-ductile transition condition of glass, obtained parameter ranges in which glass material can be milled in a plastic process.