Effects of duty cycle on the structures and properties of AlCrN coatings were investigated for improving the performances. The AlCrN coatings were synthesized by pulsed arc ion plating under different power duty cycles in nitrogen ambient. The structures, mechanical properties and corrosion resistance of the coatings were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffractometry (XRD), nanoindentation and Chi650e electro-chemical workstation. The results showed that the surface particle area fraction and roughness of the coatings gradually increased with the increase of duty cycles from 10% to 20%, then tended to be stable when further improved the duty cycles. While the thicknesses of the AlCrN coatings increased from 4.06 μm to 7.56 μm with the duty cycles increasing from 10% to 30%. When the duty cycles was less than 20%, there were many pores in the coatings; when the duty cycles was greater than 20%, the pores in the coatings were less, and the coating structure was denser. The XRD results showed that the AlCrN coatings had a cubic structure and contained nano-grains with size between 14.9~18 nm. Both the hardness and adhesion strength first increased with the duty cycles, and reached the largest values of 35.19 GPa and 81.7 N at duty cycle of 25%, then decresed with the higher duty cycles. The coating at the duty cycle of 25% exhibited the lowest self-corrosion current density and a high self-corrosion potential, indicating the excellent corrosion resistance of the coating. These results suggested that a reasonable high duty cycles could decrease the number of poles in the coaitngs and enhance the mechanical and corrosion resistance performances.