In order to improve the corrosion resistance and conductivity of SS316L bipolar plate. Cr-N thin films were prepared on SS316L bipolar plates by pulsed DC magnetron sputtering. The composition and structure of the film were detected and analyzed by scanning electron microscope, XRD diffractometer and electron probe analyzer. The conductivity, corrosion resistance and hydrophobicity of the films were characterized by contact resistance test, electrochemical corrosion test and contact angle test. The structure of the film was mainly composed of Cr and Cr2N, and the composition of each group of samples was similar. With the increase of substrate negative bias during deposition, the structure of the film became more compact. The corrosion resistance of the coated sample was better than that of the substrate SS316L. When the negative bias voltage of the substrate is 400 V, the corrosion current density of the sample was the lowest, which was 3.49×10?7 A/cm2; The conductivity of coated samples was better than that of substrate SS316L. When the substrate was negative bias voltage of 200 V, the conductivity of bipolar plate was the best, and the surface contact resistance was 8.02 mΩ.cm2. If the substrate negative bias voltage continues to increase, the contact resistance of bipolar plate will decrease. With the increase of deposition bias, the content of N in the film increases slightly. The deposition of the film significantly improved the conductivity, corrosion resistance and hydrophobicity of SS316L bipolar plate. Compared with the substrate, the self corrosion potential increased by 411 mV and the corrosion current density decreased by two orders of magnitude. The higher substrate negative bias during deposition was more significant for the improvement of the conductivity and corrosion resistance of the bipolar plate, but the higher substrate negative bias leads to the fine grains and good compactness of the film, which will affect the electrical conductivity of the film.