Objective To research the performance of coating end mill and PCD end mill on cutting aluminum ally. Methods In this paper, four-flute end mill with 1 μm diamond coating, four-flute end mill with 5 μm diamond coating and PCD end mill were taken as the objects to study the tool life and chip sticking situation, the feeding length of cutting aluminum alloy in the process of high-speed dry cutting of which was compared in the experiment, furthermore, the surface roughness of aluminum alloy was tested with the surface roughness tester. Results The results showed that the failure distance of end mill with 1 μm diamond coating or 5 μm diamond coating was 25 meter or 75 meter and that of PCD end mill was 96 meter when cutting aluminum alloy. The average surface roughness of end mill with 1 μm diamond coating or 5 μm diamond coating was 1.07 μm or 1.10 μm and that of PCD end mill was 0.80 μm. Conclusion The life of the end mill with 5 μm diamond coating was four times more than that of the end mill with 1 μm diamond coating, while the PCD end mill has the longest service life. The roughness of end mill with 1 μm diamond coating or 5 μm diamond coating was higher than that of PCD end mill when cutting aluminum alloy. PCD end mill had longer life than diamond coating end mill and could also significantly reduce the sticking situation when cutting aluminum alloy in the same cutting environment.