The present invention relates to a method for preparing a foam for impregnating a liquid-phase cosmetic material, wherein the foam can be used while impregnating a liquid-phase or solid-phase cosmetic composition, such as a solution, an emulsion, a gel, a cream, or a suspension. According to the present invention, disclosed is a method for preparing a foam for impregnating a liquid-phase cosmetic material, the method comprising the steps of: (a) preparing a polyester polyol obtained by putting a polyester polyol in a chamber, followed by deflation at a temperature of 55-65° C. and mitigation under conditions of a pressure of 0.1-0.2 kPa for 60 minutes, and then lowering the temperature to 25-35° C. followed by supply of nitrogen and mitigation under conditions of a pressure of 2-3 kPa for 48 hours (b) preparing a polyether polyol obtained by putting a polyether polyol in a chamber, followed by mitigation under conditions of a temperature of 15-25° C. and a pressure of 0.1-0.2 kPa for 60 minutes, supply of nitrogen, and mitigation under conditions of ,a pressure of 2-3 kPa for 48 hours (c) injecting and preparing a foaming agent, a catalyst, and a surfactant in tanks according to capacity demands, respectively (d) sequentially putting, in a mixing and stirring tank, the polyester polyol, polyether polyol, foaming agent, catalyst, and surfactant at a mixing ratio, and then performing continuous foaming with stirring at 5000 rpm under conditions of a temperature of 22-24° C. and a tank internal pressure of 3 kPa (e) aging, for 48 hours, a foam formed after the completion of the foaming step and (f) finishing the foam to manufacture a product.