A proton exchange membrane and method for formation the same is disclosed. When forming the proton exchange membrane, first, a bismaleimide and barbituric acid are copolymerized to form a hyper-branched polymer. Next, the solvent of the sulfonated tetrafluorethylene copolymer (Nafion) aqueous solution is replaced with dimethyl acetamide (DMAc). 10 to 15 parts by weight of the hyper-branched polymer is added to 90 to 85 parts by weight of the Nafion in the DMAc solution, stood and heated to 50° C. for inter-penetration of the hyper-branched polymer and the Nafion. The heated solution is coated on a substrate, baked, and pre-treated to remove residue solvent to complete formation of the proton exchange membrane.