The invention provides a composite metal fuel cell bipolar plate with high air permeability. The composite metal fuel cell bipolar plate comprises composite metal bipolar plates at an anode side and acathode side, and the composite metal bipolar plate comprises a metal base material and a conductive porous layer, wherein the conductive porous layer is connected to the metal base material; a flowfield is formed on the surface, facing a fuel cell gas diffusion layer, of the conductive porous layer and comprises a plurality of flow channels; a cooling liquid cavity is formed in the back surfaceof the metal base material; the composite metal bipolar plate on the anode side and the composite metal bipolar plate on the cathode side are connected back to back, and a cooling liquid cavity is formed between the two metal substrates which are connected with each other. The invention further provides a preparation method of the composite metal fuel cell bipolar plate with high air permeability. The composite metal fuel cell bipolar plate has the characteristics of high aperture ratio, high conductivity and high gas transmission, and has the advantages of convenience in processing, low preparation cost and the like.