The invention provides cool three-phase emulsification type sun-screen cosmetic and a preparation method thereof. An excellent sun-screen function is realized through an oil-in-water-in-oil three-phase emulsification mode, a cool skin sense is provided, and the disadvantage that a sun-screen product is generally sticky can be effectively improved. The cool three-phase emulsification type sun-screen cosmetic is prepared from the following components: 5 to 15 percent of oil, 0.5 to 1 percent of a surfactant, 10 to 20 percent of polyol, 10 to 20 percent of a sun-screen agent, 0.1 to 1 percent ofa thickening agent and balance of water. The preparation method of the cool three-phase emulsification type sun-screen cosmetic comprises the following steps: dispersing the surfactant and the sun-screen agent into the oil, heating to 80 to 85 DEG C, keeping warm, stirring until uniformly mixing, then stirring and cooling to 40 to 42 DEG C, and keeping warm for standby use; dispersing the polyol and the thickening agent into the water, heating to 80 to 90 DEG C, keeping warm, stirring until uniformly mixing, then stirring and cooling to 40 to 42 DEG C, and keeping warm for standby use; stirring a prepared water-phase mixture at a high speed, slowly pumping a prepared oil-phase mixture into the water-phase mixture, homogenizing, scraping non-uniform materials, then stirring and homogenizingfor several minutes, cooling to 30 to 35 DEG C, and discharging.