The invention relates to the field of polymeric nanofibers, in particular o a preparation method of polyurethane nanofiber membrane-grafted (N-isopropylacrylamide-co-acrylate) hydrogel. The preparation method comprises the steps of a, preparing polyurethane nanofiber membrane by means of thermally induced phase separation; b, preparing vinyl-modified silicon dioxide; c, grafting N-isopropylacrylamide and acrylic acid to the surface of the polyurethane nano fiber through ultraviolet radiation to obtain polyurethane nanofiber membrane-grafted (N-isopropylacrylamide-co-acrylate) hydrogel. The preparation method has the advantages that specific surface area and porosity of the hydrogel are greatly increased, and high temperature and pH response rates are imparted to the hydrogel.