Gas cooled cutting is an important branch of green machining technology with its excellent cooling performance and is used more and more widely in field of machining. A new method of developing cooling gas generator using semiconductor refrigeration is presented in this paper. Then the main principle, structure and performance of the generator are introduced. In addition, the experiments of high speed milling of Ti Alloy using cooled nitrogen gas were conducted and satisfactory results were achieved. These researches show that the new cooling gas generator has a series of merits such as simple structure, excellent performance, handy operation, low cost and significant spreading value etc.