A method for forming a protective film on a foam cushion including steps of preparing the cushion, applying a hot-melt adhesive, hot pressing a resin film, and cutting. Therein, the cushion is applied with a hot-melt adhesive layer, and a heated metal roller is used to press the resin film onto the hot-melt adhesive layer. The melting point of the resin film is greater than that of the hot-melt adhesive layer, and the heating temperature of the metal roller is between the melting point of the resin film and the melting point of the hot-melt adhesive layer, so that while the resin film is pressed on the hot-melt adhesive layer by the metal roller, the resin film is stuck by the hot-melt adhesive layer, thereby forming a protective film on the outer surface. The method features quick resin film and reliable film affixation.