CrCN coating with high melting point, high thermal conductivity, good hardness and toughness, abrasion resistance and corrosion resistance, low resistivity and other advantages. Compared to the CrN films, C elements can improve the high temperature oxidation resistance, reduce the rate of wear effectively and reduce the adhesion. Based on the characteristics of CrCN thin film with low cohesion and high internal stress, Cr/CrCn multilayer films were deposited by arc ion plating. Cr target was used as the sputtering source, the Cr layer was prepared by sputtering gas as Ar, and the CrCN layer was prepared by sputtering gas as N2 and C2H2, Cr/CrCN films with different modulation ratios were prepared by changing the N2 and C2H2 aeration time. The structural composition, hardness, elastic modulus, surface morphology, thickness and corrosion resistance of the thin films were characterized by nano indentation, electrochemical workstation, XRD, XPS, SEM, TEM, Raman and FIB. The interfacial fracture toughness and its bonding properties were tested by using a scratch tester. The testing results show that a large n mber of C element and Cr element are combined to Cr7C3 as reinforcing phase, plays an important role in improving the mechanical properties of the coating and a small amount of C element is present in the form of SP2 hybrid and improve the tribological performance of the coatings. The presence of the Cr layer interrupts the growth of the columnar crystals. It makes the film structure more compact. With the increase of the layer n mber of Cr, the binding capacity of the films increased, the hardness decreased and the toughness increased. The existence of multilayer structure hinders the extension of the crack, and the Cr and CrCN interface increase the shielding effect of the micro crack front expansion. After extending to the interface, the micro cracks tend to produce deflection and bifurcation, which hinders the further extension of micro cracks, and the toughness of the coating was improved.