The work aims to study performance comparison of Ta-C coating milling cutter and common diamond-like coating milling cutter in cutting 2A50 aluminum alloy. Experiment was performed to compare the performance of two-bladed, four-bladed Ta-C coating cutters as well as two-bladed, four-bladed common diamond-like coating cutters in cutting 2A50 aluminum alloy under the condition of dry cutting. Service life of the cutters were compared based upon cutting distance under the same cutting condition. A microscope was used to observe surface morphology of cuttings, and surface roughness tester was used to inspect roughness of aluminum alloy surface. The two-bladed Ta-C coating milling cutter had the longest service life in dry-cutting aluminum alloy, and the cutting distance was 116 m. Surface roughness of Ta-C coating milling cutter and common diamond-like coating cutter was increasing as a whole in machining workpieces. Workpieces machined with two-bladed Ta-C coating milling cutter exhibited good surface quality, the average surface roughness was 0.692 μm. Comparison of coating milling cutter in same number of blades and of good adhesion indicates that, average surface roughness of workpieces machined with Ta-C coating milling cutter is lower than that of those machined with common diamond-like coating cutter. There is no significant difference in morphology of cuttings obtained in the same mode of coating machining. Both cutters can prevent sticking effectively when cutting aluminum alloy, but Ta-C coating milling cutter prevails.