NOVELTY - The backplane comprises polyethylene terephthalate (PET) thin film substrate layer (3), a first adhesive layer arranged on one side of the PET film base body layer, a first polypropylene film, a second polypropylene film, coating agent, set at the other side of the PET film base body layer and a second adhesive layer. The adhesive layer is set on the upper part and combined by adhesive layer and PET film substrate layer.    USE - The backplane is useful for solar battery.    ADVANTAGE - The backplane has good temperature impact resistance and good electric insulation.    DETAILED DESCRIPTION - The backplane comprises polyethylene terephthalate (PET) thin film substrate layer (3), a first adhesive layer arranged on one side of the PET film base body layer, a first polypropylene film, a second polypropylene film or coating, set at the other side of the PET film base body layer and a second adhesive layer. The adhesive layer is set on the upper part and combined by adhesive layer and PET film substrate layer. The second polypropylene film is combined to the other side of the PET film base body layer through a second adhesive layer on the second polypropylene film and PET film base body layer between the coating directly to form the other side of the PET film base body layer. The first polypropylene film and the second polypropylene film have a high ultraviolet light reflectivity, and a thickness of 50-150 mu m. The first polypropylene film and the second polypropylene film is modified polypropylene film. The modified polypropylene film is prepared by mixing 50-80 parts by weight of homopolymer polypropylene, 0-20 parts by weight of high density polyethylene, low density polyethylene and ethylene copolymer for 15-30 minutes, mixing 0.1-5 parts by weight of modified polymer and 10-20 parts by weight of toughening agent, mixing for 5-15 minutes, 5-25 parts by weight of auxiliary agent and 0.1-20 parts by weight of antioxidant for 15-60 minutes to obtain the modified polypropylene film. The ethylene copolymer comprises ethylene-butylene copolymer, ethylenepropylene copolymer, an ethylene-hexene copolymer or ethylene-methyl methacrylate polymer. The modified polymer is nylon 11 and nylon 12. The toughening agent comprises maleic anhydride grafted polyolefin elastomer, maleic anhydride graft ethylene-vinyl acetate, maleic anhydride grafting styrene-butadiene-styrene block copolymer and maleic anhydride grafted acrylonitrile-styrene-butadiene copolymer. The auxiliary agent comprises nano-silicon dioxide and nano titanium dioxide. The antioxidant comprises phosphite antioxidant, organic sulfide antioxidant. The PET film base body layer is polyethylene glycol terephthalate film or modified polyethylene glycol terephthalate film. The PET film base body layer is polyethylene glycol terephthalate extinction film. The PET film base body layer has a thickness of 100-300 mu m. The coating comprises 80 parts by weight of polyethylene resin and 20 parts by weight of polyamide resin. The inorganic filler is talcum powder, calcium carbonate, calcium oxide, magnesium carbonate and barium sulfate and has grain diameter of 1-50 mu m. The adhesive layer is epoxy resin adhesive, polyurethane adhesive, acrylic ester adhesive and vinyl acetate and has thickness of 1-30 microns.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a five-layer structure of the backplane for solar battery.    Polypropylene film (1)    Adhesive layer (2)    Polyethylene terephthalate thin film substrate layer. (3)