Bipolar plate of proton exchange membrane fuel cell

The invention provides a bipolar plate of a proton exchange membrane fuel cell, which consists of a cathode plate and an anode plate, and is characterized in that the cathode plate and the anode plate are formed by stamping metal sheets, a cathode flow field is stamped on the outer side of the cathode plate, an anode flow field is stamped on the outer side of the anode plate, the cathode plate and the anode plate are attached together, and the anode plate and the cathode plate are bonded together. The cathode plate and the anode plate are integrated through laser welding or bonding, and a closed coolant flow field is formed on the inner sides of the cathode plate and the anode plate; and the areas of common channels of the cathodes, the anodes and the coolant inlets/outlets on the anode plates and the cathode plates are asymmetrically arranged. According to the bipolar plate and the flow field structure thereof, uniform distribution of reaction gas can be effectively improved, so that uniform distribution of