The bipolar plate of fuel cell needs proper surface treatment. After nickel plating on the anode side of the bipolar plate, the conductivity is good, and it is not easy to be wetted by the electrolyte, which can avoid the loss of electrolyte. The flexible contact between the electrolyte diaphragm and the bipolar plate beyond the effective area of the electrode can effectively prevent gas leakage, which is the so-called "wet seal". In order to reduce the corrosion of molten carbonate on stainless steel at the "wet seal" position, the bipolar plate frame needs to be "aluminized" for protection