Metal pole plate surface protective coating, preparation method and application thereof and metal pole plate

The invention discloses a metal polar plate surface protective coating, a preparation method and application thereof and a metal polar plate, and relates to the technical field of fuel cell manufacturing. Comprising a connecting layer and an amorphous carbon layer which are sequentially coated on the surface of a metal pole plate, the amorphous carbon layer comprises a plurality of conductive layers and corrosion-resistant layers which are alternately arranged, and the sp2 hybrid bond content of carbon atoms in the conductive layers is greater than or equal to 70%; and the sp3 hybrid bond content of carbon atoms in the corrosion-resistant layer is greater than or equal to 70%. In the coating provided by the invention, the sp2 hybrid bond content of carbon atoms of the conductive layer is high, and the conductivity of the coating is good; the sp3 hybrid bond content of carbon atoms in the corrosion-resistant layer is high, and the corrosion resistance is high. The corrosion resistance of the metal pole plate c