Abstract: In view of the high cutting force, high temperature and low tool life caused by the difficult machining characteristics of titanium alloy, the milling experiments of titanium alloy under the condition of low temperature liquid nitrogen cooling are carried out by developing a liquid nitrogen cooling application device integrated with NC machine tool. The cutting force and surface roughness of milling titanium alloy are measured by dry cutting, cutting fluid pouring, minimal quantity lubrication and liquid nitrogen cooling. And the influence of cooling method on tool failure form under different machining conditions are also studied. The results show that, when the cutting speed is more than 120m/min, the low-temperature liquid nitrogen cooling is beneficial to reduce the cutting force and surface roughness. And it can effectively inhibit the generation of tool breakage, which can improve the tool life more effectively than the method of cutting fluid pouring.