TECHNOLOGY FOCUS - POLYMERS - Preparation: The preparation method of the proton transmitting film of sulfonated polypyrron comprises (1) preparing sulfonated polypyrron by adding the monomer 1 and monomer 2 to three reactors with mole ratio of 1:1, filling nitrogen to eliminate oxygen, adding solvent m-cresol to make the solid content of the solution being 100-150 mg/ml, adding benzoic acid with two times mole ratio to the monomer 1 as the catalyst and triethylamine with two times mole ratio to the monomer 1 to damage polymer to form the internal salt, mechanically stirring the solution till dissolving at 80 degrees C, heating at 180-200 degrees C, reacting for 10-15 hours, adding m-cresol solvent to dilute the high concentration solution to make the solid content of the solution be 50-80 mg/ml, cooling at 80 degrees C, pouring the solution in the acetone, stirring and filtering, collecting the deposition, washing the deposition by the acetone reflow for 4-8 hours, filtering, collecting the deposition, drying to prepare the sulfonated polypyrron; adding the quantitative monomer 3 to three reactors, filling nitrogen to eliminate oxygen, adding solvent m-cresol to make the solid content of the solution be 100-150 mg/m, stirring, adding triethylamine with two times mole ratio to the monomer 3, dissolving the monomer 3, adding monomer 4 with equal mole ratio of monomer 3 and benzoic acid with two times mole ratio to the monomer 3 as the catalyst, mechanically stirring at 80 degrees C to completely dissolve, reacting for 10-15 hours, adding m-cresol solvent to dilute the high concentration solution to make the solid content of the solution be 50-80 mg/ml, cooling the solution at 80 degrees C, pouring the solution in acetone, stirring and filtering, collecting the deposition, washing the deposition by the acetone reflow for 4-8 hours, filtering, collecting the deposition, drying to prepare the sulfonated polypyrron; and adding the monomer 2 and monomer 3 to three reactors with any ratio, filling nitrogen to eliminate oxygen, adding solvent m-cresol to make the solid content of the solution be 100-150 mg/ml, stirring at room temperature, adding the triethylamine with two times mole ratio of the monomer 3, dissolving the monomer 2 and the monomer 3, adding the monomer 1 where the mole ratio summation of the monomer 2 and the monomer 3 equals to the mole ratio of the monomer 1, adding the triethylamine with two times mole ratio of monomer 1 to prevent the polymer forming the internal salt, finally adding the benzoic acid with two times mole ratio to the monomer 1 as the catalyst, mechanically stirring the solution till dissolving at 80 degrees C, heating at 180-200 degrees C, reacting for 10-15 hours, adding m-cresol solvent to dilute the high concentration solution to make the solid content of the solution be 50-80 mg/ml, cooling the solution at 80 degrees C, pouring the solution in the acetone, stirring and filtering, collecting the deposition, washing the deposition by the acetone reflow for 4-8 hours, filtering, collecting the deposition, drying to prepare the sulfonated polypyrron; and (2) preparation of proton transmitting film of sulfonated polypyrron by dissolving the dry sulfonated polypyrron polymer into the m-cresol where the solid content of the polymer is 80-100 mg/ml, filtering, pouring the filtrate on the clean glass plate, drying for 24 hours at 70 degrees C, then drying for 12 hours at 120 degrees C, taking off from the glass plate, then placing it in the sulfuric acid solution with concentration of 2 mol/L, maintaining for two days at room temperature, then washing with a large quantity of water to prepare the proton transmitting film of sulfonated polypyrron.