The invention relates to a method for preparing a pollution preventing self-cleaning polyvinylidene fluoride (PVDF) film and a product thereof. The method comprises the following processes: (1) PVDF film preparation; and (2) PVDF film processing with alkali liquor, including an alkali-water solution processing process and an alkali-alcohol solution processing process, wherein the alkali-water solution processing process comprises the following steps: soaking the PVDF film in alkali-water solution with the mass concentration of 20-40 percent; processing at 60-80 DEG C for 2-3 hours and then taking out to wash with water; drying and obtaining the PVDF film; the alkali-alcohol solution processing process comprises the following steps: soaking the PVDF film in alkali-alcohol solution with themass concentration of 2-10 percent; processing at 25-40 DEG C for 3-5 minutes and then taking the film out; washing with water and drying; soaking the PVDF film in proper solution to react at 25-60 DEG C for 3-10 minutes; then taking out and fully washing with water; drying and then obtaining the PVDF film; (3) decorating the surface of the PVDF film by organosilane and preparing the pollution preventing self-cleaning polyvinylidene fluoride film. The pollution preventing self-cleaning PVDF film product is prepared by the method.