In this paper， the typical hard-to-cut Cr12MoV die steel is taken as the research object. ABAQUS is used to conduct numerical simulation of the temperature field under electric spark discharge. Experimental results of the traditional milling and electric spark assisted milling are compared under different feed rates. By means of a high-speed camera， scanning electron microscope and dynamometer， the characteristics of cutting force， surface morphology and tool wear are analyzed and studied. The results show that the cutting force of EDM-assisted milling is 28.57%-51.47% lower than that of traditional milling， and the surface roughness is reduced by 2/3. Compared with traditional milling， EDM-assisted milling has significant advantages in reducing cutting force，improving surface quality and reducing tool wear.