Abstract: The high-entropy alloy Ni₄₀Fe₃₀Co₂₀Al₁₀ has a combination of excellent properties such as high plasticity, high strength, high hardness and corrosion resistance at low temperatures, and has a large potential for application in the aerospace field. However, insufficient cooling during cutting leads to high cutting temperature and serious damage to the machined surface. For the high cutting temperature problem of high-entropy alloys, the cutting method of cryogenic cooling with micro liquid nitrogen was adopted to avoid the problem of high dry cutting temperature and local overcooling with large flow liquid nitrogen cooling. The test results of end face turning show that cryogenic cooling with micro liquid nitrogen can improve the machining surface quality. The tool wear mechanism under different working conditions was studied, and based on this mechanism, the influence of cooling conditions and cutting speed on the machining surface integrity was revealed. The machined surface quality can be significantly improved by the use of cryogenic cooling with micro liquid nitrogen in high-speed cutting. The causes of work hardening and the depth of hardened layer under different cooling conditions and cutting speeds are revealed by combining the changes of cutting temperature and cutting force.