NOVELTY - A solar cell protective film comprises modified polytetrafluoroethylene membrane deposited on a thin film formed by Magnesium fluoride, titanium dioxide-Zirconium dioxide-lanthanum oxide and aluminum oxide film, where the modified film has thickness of 50-100 nm, Magnesium fluoride film thickness is 90-95nm, modified polytetrafluoroethylene membrane is prepared by adding kerosene surfactant with epoxy resin, stirring and continue stirring mix before adding poly tetrafluoroethylene resin powder, to obtain mixture, and placing second mixture in an inert atmosphere.    USE - Protective film for use in solar cell or photovoltaic solar cell (claimed).    ADVANTAGE - The film has high photovoltaic performance, long life, abrasion wear scratches, and excellent mechanical properties.    DETAILED DESCRIPTION - A solar cell protective film comprises modified polytetrafluoroethylene membrane deposited on a thin film formed by Magnesium fluoride, titanium dioxide-Zirconium dioxide-lanthanum oxide and aluminum oxide film, where the modified film has thickness of 50-100 nm, Magnesium fluoride film thickness is 90-95nm, the film thickness of the titanium dioxide-Zirconium dioxide-lanthanum oxide film is 500-800nm, and aluminum oxide film thickness is 70-80nm, and the modified polytetrafluoroethylene membrane is prepared by adding kerosene surfactant with epoxy resin, stirring and continue stirring mix before adding poly tetrafluoroethylene resin powder, to obtain mixture, placing the mixture at 10-18 degrees C, stirring a uniform mixture at speed of 20-80 rpm, to give a second mixture, placing second mixture in an inert atmosphere at 5-30 degrees C to obtain curing material, molding the material obtain the finished product, after the mold left to stand for 1-48 hours, heat treating at 10-20 degrees C/min, room temperature of 320-330 degrees C, heating rate of 5-6 degrees C/min, for 1 h, treating resulting molded products, at -5 to 5 degrees C, rapid cooling for 30min, natural drying, slicing low temperature sample, at thickness of 50-100 mu m, utilizing hydrogen plasma ion and hydroxyl modified ozone plasma after slices modified, in vacuum degree of elevated temperature conditions of 3.5x 103Pa, and at 148 degrees C to obtain product.