The invention relates to a silver plating layer post processing method for a metal bipolar plate. The silver plating layer post processing method comprises the following steps: soaking the mixed liquid comprising polytetrafluoroethylene (PTFE) emulsion and nano-grade silver powder on the surface of a silver plating layer of a metal bipolar plate in vacuum; heating the metal bipolar plate soaked with the mixed liquid comprising the PTFE emulsion and the nano-grade silver powder in a vacuum oven or an oven with inert gas shielding, fusing and recrystallizing the PTFE and the nano-grade silver powder and volatilizing water and additive in the PTFE emulsion to obtain the metal bipolar plate silver plating layer without defects. The invention has the advantages that the pinhole corrosion is greatly reduced and the service life of the metal bipolar plate is prolonged by the porosity reduction of the plating layer, particularly the reduction of through holes; the hole filling part has hydrophobicity so as to further reduce the corrosion probability of the position in a cell environment; and the preparation process is simple and has low cost and great mass production application potential.