Abstract: The present invention relates to a fuel cell high-performance bipolar plate with a surface titanium-tantalum-carbon thin film and its preparation method, which belongs to the technical field of fuel cell and material surface modification. The bipolar plate consists of 316L stainless steel or TA1 titanium sheet bipolar plate substrate and titanium-tantalum nanocrystalline transition layer on its surface, and titanium-tantalum-carbon amorphous nanocrystalline composite film on the outermost surface; titanium-tantalum nanocrystalline transition layer and titanium-tantalum-carbon amorphous nanocrystalline composite film are prepared by a new arc ion coating method, in which the removal of passivation film and surface activation of the substrate before plating the transition layer, and the removal of defects such as large particles in the transition The removal of the substrate passivation film and surface activation before plating the transition layer, as well as the removal of large particles and other defects in the transition layer before plating the most surface composite film, are carried out by ion sputtering with etching using a plasma-enhanced discharge supplemented by a gas ion beam. The bipolar plates prepared by this method have high comprehensive performance and can meet the requirements for ultra-long lifetime operation of the battery stack.