With the development of green cutting technology, the low-temperature MQL technology emerged. In order to solve the problem that caused by cutting heat, it adds the low-temperature air on the foundation of MQL. In the view of low-temperature MQL studies which could reduce the cutting force, we have done a lot of experiments and theoretical pushovers. The experimental results show that the most important reason why the low-temperature MQL can reduce the cutting force effectively is a reliable lubricant film that between tool and chip. It describes the forming process of the oil film and derives the friction coefficient relationship between dry cutting and oil film cutting.