NOVELTY - Preparation of proton exchange membrane comprises mixing solution with tungsten with 10% perfluorinated sulfonic acid resin solution (10-20 pts.vol.), adjusting ratio of tungsten trioxide to perfluorinated sulfonic acid resin in mixed solution with organic solvent, ultrasonically treating solution for 1-3 hours, pouring membrane solution in horizontal mold, heating solution for 3-15 hours at constant temperature to obtain proton exchange membrane with thickness of 50-250 mu m.    USE - Method of preparation of proton exchange membrane used for direct methanol fuel cell (claimed).    ADVANTAGE - The membrane produced has high alcohol resistance performance, high conductivity of proton and simple technique, and suitable for industrial production.    DETAILED DESCRIPTION - Preparation of proton exchange membrane comprises:    (A) dissolving tungsten powders into 30% hydrogen peroxide solution (12-32 pts.vol.), adding isopropyl alcohol (6-12 pts.vol.) and deionized water (6-12 pts.vol.), standing reaction solution for 24-48 hours, completely dissolving tungsten powders and filtering solution to obtain solution with tungsten;    (B) mixing solution with tungsten with 10% perfluorinated sulfonic acid resin solution (10-20 pts.vol.), adjusting ratio of tungsten trioxide to perfluorinated sulfonic acid resin in mixed solution with organic solvent, the ratio of tungsten trioxide and perfluorinated sulfonic acid resin to volume of mixed solution at 1-20%, stirring mixed solution, ultrasonically treating solution for 1-3 hours, standing solution until there is basically not bubble, and defoaming to prepare membrane solution;and    (C) pouring membrane solution in horizontal mold, heating solution at speed of 2 degrees C/minute to 50-80 degrees C, heating solution for 0.5-2 hours at constant temperature, continuously heating solution, when solution is heated at 120-150 degrees C, heating solution for 3-15 hours at constant temperature to obtain proton exchange membrane with thickness of 50-250 mu m.