In order to reduce the cutting force and improve the machining quality,ultrasonic vibration was introduced into the milling of titanium alloy to realize the periodic contact and separation of cutter and workpiece.Taking TC4 as the research object and cutting force as the research breakthrough point,a 3D milling simulation model was established through ABAQUS.The differences between ultrasonic milling and ordinary milling in the cutting force curve characteristics and numerical values were compared and analyzed,and the fluctuation and stability of the cutting force were analyzed by observing the chip characteristics.The results show that axial vibration milling is beneficial to reduce the cutting force and improve the cutting stability.