CrNx/CrC composite coatings were deposited on the substrate of single crystal silicon and 304 stainless steel by the high power impulse magnetron sputtering (HiPIMS), and the morphology structure, phase and corrosion resistance were analyzed by scanning electron microscope (SEM), X-ray diffraction technology (XRD) and immersion method. The effects of nitrogen flow on the microstructure and corrosion resistance of CrNx/CrC composite coating were studied. The results show that Cr target can form a steady pulse discharge with high power under an electric field of 200 Hz and a duty cycle of 6%. The surface of CrNx/CrC composite coating is composed of irregular spherical particles, which are uniform and compact. The CrNx/CrC composite coating grows in columnar form, and obvious stratification interfaces are observed in the cross section, which are CrNx layer and CrC layer respectively. With the increase of nitrogen flow, the thickness and average deposition rate of CrNx/CrC composite coating increase slightly and then decrease obviously due to the decrease of Ar+ etching effect. With the increase of nitrogen flow, the density of the coating increases slightly. When the nitrogen flow is 60 mL·min-1, the distance between the crystal columns of the coating is the smallest, and the upper and lower layers are most closely combined, and the corrosion resistance is the best.