The milling process has been widely used for manufacturing aeronautical materials. It is very important to choose the reasonable milling parameters for improving the machining accuracy and surface quality. In this paper, the orthogonal experiments are made to construct the relationships between the milling force and milling parameters to TA15 titanium alloy. And the milling parameters mainly include milling speed, milling depth, milling width and feed engagement. And the empirical equations of milling force are gotten by regression analysis, and the equations are tested to be correct by the single factor experiment. The result is quite important for further research on the milling performance and can serve as a reference to production of titanium alloys.