Abstract: Using AlTiN coated 4-edge φ10 mm carbide end milling cutter, the milling finishing experiment of TC4 titanium alloy was carried out on VMC850 vertical machining center.The surface roughness, flatness, parallelism, surface morphology, residual stress and microhardness of the machined TC4 titanium alloy specimen were measured by using high precision digital testing equipment.The overall machining quality and surface morphology of TC4 titanium alloy with AlTiN coated tool under different process parameters were analyzed.The results show that under the optimal finishing process parameters of spindle speed n=8 000 r/min, feed per tooth f_z=0.04 mm/z, and cutting depth Δd=0.5 mm, TC4 titanium alloy workpiece has good machining quality and surface morphology, long tool life, flatness of 0.39 μm, parallelism of 0.33 μm, surface roughness of 0.70 μm, surface residual stress of -175 MPa, and surface microhardness of 269 HV_0.2, thus realizing high-quality and high-efficiency finishing of TC4 titanium alloy.