A semi-artificial thermocouple device is developed to explore the dynamic cutting temperature variation rules in high-speed milling of Al7050-T7451 aluminum alloy. Both the aluminum-constantan thermocouple calibration diagram and cutting temperature curves are obtained. The cutting temperature empirical formula is constructed by means of orthogonal experimental design and multivariate linear regression analyses. It shows a reasonable good match between the theoretical predicted values and the measured temperatures. This allows for the optimization of cutting parameters and the exploration of machining deformation induced by the cutting heat in high-speed milling of aerospace aluminum monolithic constructions.