A finite element model of helix double-edge cutting was developed to study cutting temperature during milling of titanium alloy Ti6Al4V. To improve the accuracy of finite element simulation, a new method to construct material constitutive model was presented, and material constitutive model with big strain, high strain rate, and high-temperature characters for aeronautical titanium alloy in cutting process was established. Using this finite element model, milling process of titanium alloy was simulated. Cutting temperature change curves and values were obtained. An analysis indicates that the highest cutting temperature lies in tool-chip interface and is more close to cutting edge; moreover, the temperature is higher in rake face than flank face of the tool. The embedded semi-artificial thermocouple cutting temperature experiment was improved by substituting constantan band for constantan wire. By comparing the results obtained from finite element simulation and cutting temperature experiment results, a good agreement is found, showing finite element simulation analysis of cutting temperature for titanium alloy is correct.