Abstract: 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.