NOVELTY - Fuel cell proton exchange composite membrane is prepared by preparing sodium imidazole, preparing silicon nanoparticle precursor, adding silicon nanoparticle precursor (TPSIm) to polybenzimidazole solution, adjusting mixture pH, stirring, uniformly coating solution in glass sheet, drying , soaking in deionized water, peeling film from glass plate, soaking in methanol for 8 hours to remove solvent, washing film with deionized water, drying in electrothermal vacuum oven at 100 degrees C for 24 hours to obtain composite film with 60-100 mu m, and 5-20 mass% TPSIm.    USE - Preparation of fuel cell proton exchange composite membrane (claimed).    ADVANTAGE - The preparation of fuel cell proton exchange composite membrane is simple, controllable, improves adsorption capacity of phosphate and phosphate leaching inhibition, increases proton conductivity, and yields high temperature resistant product.    DETAILED DESCRIPTION - Fuel cell proton exchange composite membrane is prepared by dissolving polybenzimidazole in dimethyl sulfoxide with ratio 1 g:10-20 ml, heating to completely dissolve until solution turns to brown transparent solution, mixing sodium ethoxide and imidazole with molar ratio 1:1 in absolute ethyl alcohol, magnetically stirring at 70 degrees C for 8 hours, rotary evaporating to remove absolute ethyl alcohol solvent, vacuum drying at 50 degrees C for 6 hours to obtain sodium imidazole, mixing gamma -chloropropyl triethyoxysilane and imidazole with molar ratio 1:1 in absolute methanol, stirring at room temperature for 24 hours to react, filtering off solids, rotary evaporating to remove absolute methanol solvent and obtain silicon nanoparticle precursor, adding TPSIm to polybenzimidazole solution, dropwise adding hydrochloric acid to adjust mixture pH to 2, stirring at room temperature for 6 hours, uniformly coating solution in clean, smooth glass sheet, drying in electrothermal vacuum oven at 80 degrees C for 6 hours, soaking in deionized water, peeling film from glass plate, soaking in methanol for 8 hours to remove solvent, washing film with deionized water, drying in electrothermal vacuum oven at 100 degrees C for 24 hours to obtain composite film with 60-100 mu m, and 5-20 mass% TPSIm.    DESCRIPTION OF DRAWING(S) - The drawing shows a graph of proton conductivity of composite film containing different dopant ratio.