To achieve green cutting of titanium alloy Ti-6Al-4V with water steam cooling and lubricating, a 600-800w minitype generator is developed. Compared to dry and water-based emulsion, the using of water steam decreases the main cutting force and the cutting temperature respectively; enhances the machined surface appearance. And it can help to chip forming and breaking. Water steam application also improves Ti-6Al-4V machinability and prolongs the tool life. The excellent cooling and lubricating action of water steam could be summarized that water molecule has polarity, small diameter and high speed, can be easily and rapidly to proceed adsorption in the cutting zone. The results indicate that the using of water steam has the potential to attain the green cutting of titanium alloy.