High-entropy alloy of NiCoCrFeMnCuC were made by vacuum non-consumable arc furnace in the present work. The crystal structure of NiCoCrFeMnCuC was analyzed by XRD. The corrosion resistance of NiCoCrFeMnCuC in 10%HNO3-3%HF, 10%H2SO4, 5%HCl and 10%HF was investigated, respectively with weight loss experiment. The results show that main intermetallics of the alloy are CoCx, FeNi3 and Fe3Mn7. The NiCoCrFeMnCuC has simple crystal structures with face-centered cubic crystal structure FCC and Quartet and has excellent corrosion resistance in some medium acid liquids.