NOVELTY - A polyamide backplane comprises an inner surface layer, a core layer, and an outer surface layer from the inside to the outside. The inner surface layer and the outer surface layer are made from polyamide resin, fillers and additives. The core layer is made from a modified polyamide resin composition. The modified polyamide resin composition comprises a polyamide resin, grafted polyethylene, a polypropylene resin, fillers and additives.    USE - Polyamide backplane for solar energy assembly.    ADVANTAGE - The polyamide backplane has excellent adhesion, peel force, aging resistance, low saturation water absorption rate, low water vapor transmission rate and excellent electric insulation, simple preparation, and low cost, and is suitable for industrial production.    DETAILED DESCRIPTION - A polyamide backplane comprises an inner surface layer, a core layer, and an outer surface layer from the inside to the outside. The mass ratio of the inner surface layer to the core layer to the outer surface layer is 10-20:60-80:10-20. The inner surface layer and the outer surface layer are made from polyamide resin, fillers and additives. The core layer is made from a modified polyamide resin composition. The modified polyamide resin composition comprises a polyamide resin, grafted polyethylene, a polypropylene resin, fillers and additives. The additive is antioxidants, UV absorbers or light stabilizers. The core layer comprises a modified polyamide resin composition. The change polyamide resin composition comprises 5-75 pts. wt. polyamide resin, 5-75 pts. wt. polypropylene resin, 5-50 pts. wt. grafted polyethylene, 0-100 pts. wt. filler and 0.1-1.5 pts. wt. additive. The additive is antioxidants, UV absorbers or light stabilizers. The polypropylene resin is a homopolymer polypropylene resin, a copolymer or a mixture of a polypropylene resin. The graft polymer ethylene is obtained by graft reaction of 100 pts. wt. polyethylene resin, 0.5-2 pts. wt. grafting agent, and 0.03-0.2 pts. wt. initiator. The polyethylene resin is polyethylene homopolymer and/or polyethylene copolymer. An INDEPENDENT CLAIM is included for preparation of polyamide backplane comprising:    (A) mixing uniformly polyethylene resin, grafting agent and initiator, extruding and machining, preparing modified polyamide resin composition;    (B) adding the rest component to the grafted polyethylene and mixing uniformly, and screw melting process to obtain the modified polyamide resin composition, screw rod A, a screw rod B and screw rod C; and    (C) preparing the modified polyamide solar backboard, adding inner surface layer, core layer and outer surface layer to the three layer co-extrusion sheet machine, extruding, casting, cooling, traction and coiling to obtain the polyamide backplane.