Abstract: A dual-material co-injection molded bipolar plate and its manufacturing method are disclosed, in which the manufacturing method comprises the steps of: injecting a skin polymer melt containing a first conductive material into a mold cavity of a bipolar plate mold; sequential or simultaneous injecting a core polymer melt containing a second conductive and the skin polymer melt into the mold cavity; molding a bipolar plate, being a sandwich structure having a core layer packed inside a skin layer, while enabling a conductive grid composed of the first conductive material and the second conductive material to be formed between the core layer and the skin layer for improving the through-plane conductivity of the bipolar plate.