NOVELTY - Polyethylene composite thin film comprises bonding layer of polyethylene, inorganic filler, intermediate layer of polyethylene and ethylene vinyl acetate, functional auxiliary agent and laminated layer of polyethylene. The bonding layer of polyethylene is blended with inorganic filler by using polyethylene wax (H1-wax 1105A). The bonding layer of polyethylene is adhered to intermediate layer of polyethylene and ethylene vinyl acetate, functional auxiliary agent and laminated layer of polyethylene by the use of adhesive (polyethylene wax having low melting point).    USE - Polyethylene composite thin film used for preparing solar back plate (claimed).    ADVANTAGE - The polyethylene composite thin film is easy processable.    DETAILED DESCRIPTION - Polyethylene composite thin film comprises bonding layer of polyethylene, inorganic filler, intermediate layer of polyethylene and ethylene vinyl acetate, functional auxiliary agent and laminated layer of polyethylene. The bonding layer of polyethylene is blended with inorganic filler by using polyethylene wax (H1-wax 1105A). The bonding layer of polyethylene is adhered to intermediate layer of polyethylene and ethylene vinyl acetate, functional auxiliary agent and laminated layer of polyethylene by the use of adhesive (polyethylene wax having low melting point). The polyethylene composite thin film comprises (in wt.%): functional auxiliary agent (2), polyethylene wax (5-10) and inorganic filler content (5-10). The three layers are adhered together by casting or film blowing method to obtain polyethylene composite thin film. An INDEPENDENT CLAIM is included for a method for preparing scope, which involves:    (A) weighing (in wt.%): polyethylene wax (5-10), antioxidant (0.1-0.15) and light stabilizer (0.1-0.3);    (B) blending, extruding and granulating the raw materials to obtain polyethylene blend;    (C) preparing bonding layer of polyethylene;    (D) weighing (in wt.%): inorganic filler (5-10), antioxidant (0.1-0.15) and light stabilizer (0.1-0.3) and blending them to obtain mixture;    (E) extruding and granulating the mixture to obtain intermediate layer of polyethylene;    (F) weighing (in wt.%): polyethylene wax with low melting point (5-10), antioxidant (0.1-0.15) and light stabilizer (0.1-0.3) and blending, extruding and granulating them to obtain laminated layer of polyethylene; and    (G) coextruding the three layers by using casting method to obtain polyethylene composite thin film.