NOVELTY - A solar-powered back plate comprises an inner surface layer, a core layer and an outer surface layer in mass ratio of (10-20):(20-40):(40-60) from inside to outside. The inner surface layer is made of polyethylene resin or ethylene vinyl acetate copolymer resin, a filler and an additive. The outer surface layer is made of polyamide resin, a filler and an additive. The core layer is made of crosslinked polyethylene resin composition. The additive contained in outer surface layer and inner surface layer is chosen from antioxidant, ultraviolet absorbent and light stabilizer.    USE - Solar-powered back plate.    ADVANTAGE - The solar-powered back plate has excellent adhesion, electric insulating property, high interlaminar peeling strength, aging resistance, and damp-heat aging resistance, low saturated water absorptivity and low water vapor transmittance, and is easily and economically manufactured.    DETAILED DESCRIPTION - A solar-powered back plate comprises an inner surface layer, a core layer and an outer surface layer in mass ratio of (10-20):(20-40):(40-60) from inside to outside. The inner surface layer is made of polyethylene resin or ethylene vinyl acetate copolymer resin, a filler and an additive. The outer surface layer is made of polyamide resin, a filler and an additive. The core layer is made of crosslinked polyethylene resin composition. The additive contained in outer surface layer and inner surface layer is chosen from antioxidant, ultraviolet absorbent and light stabilizer. The core layer is formed using crosslinked polyethylene resin composition. The crosslinked polyethylene resin composition comprises 100 parts mass crosslinked polyethylene resin, 0-50 parts mass grafted polyethylene, 0.1-0.5 parts mass catalyst, 0-100 parts mass filler and 0-2.5 parts mass additive. The crosslinked polyethylene resin is obtained from 100 parts mass polyethylene resin, 0-50 parts mass silane, and 0.03-0.2 initiator. The polyethylene resin is chosen from polyethylene resin homopolymer, its copolymer or mixture. The grafted polyethylene is obtained by grafting reaction of 100 parts mass polyethylene resin using 0.5-2 parts mass grafting agent and 0.03-2 parts mass initiator. An INDEPENDENT CLAIM is included for manufacture of solar-powered back plate, which involves uniformly mixing polyethylene resin, silane and initiator, extruding and machining by screw, obtaining crosslinked polyethylene resin, uniformly mixing polyethylene resin, grafting agent and initiator, extruding and machining by a screw rod, obtaining grafted polyethylene, preparing inner surface layer, outer surface layer and core layer, extruding, casting, cooling, and coiling.