To solve the problems caused by high temperature in the cutting zone during high-speed milling of Titanium alloys, some cooling methods are employed, such as cold air cooling, high pressure coolant jet impinging, MQL, etc. But all have their shortfalls, both in cooling efficiency and environmental pollution. Here a new high efficiency cooling technology-cryogenic pneumatic mist jet impinging (CPMJI) cooling technology is offered. In this technology, a little quantity of coolant is carried by high pressure cryogenic air (-20) and reaches the machining zone in the form of mist jet. This paper mainly focuses on the cooling effects of CPMJI in high-speed milling of Titanium alloy Ti-6Al-4V, as compared with dry, cold air cooling and MQL conditions. CPMJI greatly reduced the temperature in cutting zone and flank wear of tool.