The invention discloses a photothermal evaporation material integrating light absorption and thermal insulation, comprising a heat insulator and a light absorber that covers the external surface of the heat insulator, the light absorber is vertically-oriented graphene, the heat insulator is a graphene foam, and the vertically-oriented graphene and graphene foam are connected by covalent bonds; the light absorber is vertically-oriented graphene whose surface is modified with hydrophilic functional groups. The invention also discloses a method for fabricating the photothermal evaporation material integrating light absorption and thermal insulation. The invention also discloses a solar energy photothermal seawater desalination device and a high-temperature steam sterilization device. The photothermal evaporation material integrating light absorption and thermal insulation overcomes the problem of easy separation between the light absorber and the heat insulator, realizes rapid and efficient photothermal evaporation, and improves the stability and photothermal conversion efficiency of the solar photothermal seawater desalination device and the high-temperature steam sterilization device.