Abstract: In order to optimize the milling technology of Ti40 burn resistant titanium alloy, experimental study on milling parameters is carried out based on the principle of optimal cutting temperature. Firstly, the orthogonal experiment is carried out to build the empirical formula for milling temperature and parameters through regression analysis, and the effect of each parameter on milling temperature is analyzed. Secondly, the single factor experiment is conducted to determine the optimal cutting temperature value. Also, the empirical formula for the optimal milling temperature and milling parameters is obtained and validated with experiments. Finally, comparison analysis of the surface roughness under different milling temperature is completed. It is shown that the optimal milling temperature of Ti40 burn resistant titanium alloy is around 437 ℃, tool wear results is consistent with the optimal parameters, and better surface roughness with the optimal parameters can be acquired than common parameters. This investigation shows that it is reliable to optimize the cutting technology using the principle of the optimal temperature.