TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The core layer thin film is 0.01-0.3 mm thick. The ethylene-vinyl acetate copolymer thin film is 0.1-0.3 mm thick. The thickness of ethyl acetate copolymer film is 0. 0.1-0.2 mm. The core layer thin film is prepared by preparing 100 pts.wt. of polyterephthalate resin, poly(trimethylene terephthalate) resin, poly(l,4-cyclohexylene dimethylene terephthalate) resin or polyethylene naphthalate resin, uniformly mixing with 0.02-1.5 pts.wt. antioxidant and 0.1-1.5 pts.wt. hindered amine UV stabilizing agent, extruding and shaping. The ethylene-vinyl acetate copolymer thin film comprises (pts.wt.) EVA particle (100) containing 28-42% vinyl acetate, compatibilizer particle (1-10), peroxide (0.5-2.0), antioxidant (parts of), hindered amine UV stabilizing agent (0.1-1.5), and silane coupling agent (0.1-4.0) which are uniformly mixed, extruded at 60-110 degrees C, cooled, drawn and coiled. The antioxidant is tetra( beta -(3, 5-ditertiary butyl-4-hydroxy phenyl) propionic acid) pentaerythritol ester, beta -(3,5-ditertiary butyl-4-hydroxy phenyl) propionic acid octadecanol ester, phosphorous acid tris(monononyl benzene and dinonyl benzene), bis(2,4-ditertiary butyl phenyl) pentaerythritol diphosphite ester or tris(2,4-ditertiary butyl phenyl) phosphite ester. The UV stabilizing agent is bis(0,2,6,6-tetramethyl-4-piperidyl) sebacate, phosphorous acid tris(1,2,2,6,6-pentamethyl piperidine ester), bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate or bis(1-octyl oxo-2,2,6,6-tetramethyl-4-piperidyl) sebacate which belong to hindered anime. The compatibilizer is ethylene-methyl acrylic acid copolymer, ethylene-acrylic acid copolymer or maleic anhydride grafted ethylene-vinyl acetate copolymer. The mol content of carboxylic acid group is 0.5-30%. The coupling agent is vinyl triethoxy silane, gamma -aminopropyl triethoxy silane, gamma -methyl acyloxy ethyl trimethoxy silane and/or gamma -glycidyl ether propyl trimethoxy silane. The peroxide is 2,5-dimethyl-2,5-bis(tertiary butyl peroxide) hexane, tertiary butyl peroxide carbonic acid-2-ethyl hexyl ester, 1,1-(diperoxide tertiary butyl)-3,3, 5-trimethyl cyclohexane and/or butyl perbenzoate.