NOVELTY - A hybridized film, comprises sulfonated polyether ketone and sulfonated silica microspheres, where the thickness of the hybridized film is 55-80 microns, sulfonation degree of the sulfonated polyether-ether-ketone is 45-75%, and mass ratio of the sulfonated polyether-ether-ketone and sulfonated silicon dioxide microsphere is (0.80-0.95):(0.20-0.05).    USE - Hybridized film for use in separating carbon dioxide-methane in gas (claimed).    ADVANTAGE - The hybridized film contains easily obtainable raw materials, and can be prepared in controllable manner, and has high selectivity of 29-50 and permeability of 699-1321 barrer.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for preparing the hybridized film, which involves preparing silica microspheres with diameter of 100-800 nm by dispersing tetraethyl orthosilicate (TEOS) and 25 mass% ammonia in absolute ethanol, stirring the mixture at room temperature for 24 hours, adding 3-(trimethoxysilyl)propyl-2-methyl-2-propenoate and TEOS to the mixture, stirring the mixture at room temperature continuously for 24 hours, centrifuging the mixture, washing the mixture with water for 3 times, washing the mixture with ethanol, and drying the mixture to obtain double bond-modified fine silica microspheres, where the mass ratio of the TEOS and ammonia is (0.5-10):1, and mass ratio of the 3-(trimethoxysilyl)propyl-2-methyl-2-propenoate and TEOS is (1-20):1. The silica microspheres, styrene sulfonate, styrene and 2,2-azobisisobutyronitrile in mass ratio of 15:(10-30):(10-30):1 are dispersed in acetonitrile to obtain 1-5 mass% suspension. The suspension is added into reaction vessel and heated. The hot mixture is free-polymerized to form polymer layer on the silica surface of microspheres. The thickness of the polymer layer is adjusted by controlling reaction time and centrifuged. The obtained mixture is washed and dried to obtain sulfonated silica microspheres. The sulfonated polyether-ketone is added to N,N-dimethylacetamide to obtain 5-15% sulfonated polyether-ketone solution, where the mass ratio of the sulfonated polyether-ketone and silica microspheres in the sulfonated polyether-ketone solution is (0.80-0.95):(0.20-0.05). The sulfonated silicon dioxide microsphere is dispersed in N,N-dimethylacetamide and processed ultrasonically for 12-36 hours. 10% sulfonated polyether-ketone solution is added to the mixture and stirred for 24 hours. The obtained mixture is maintained for 1-3 hours and defoamed to obtain casting film liquid. The obtained liquid is poured into culture dish and dried at 60 degrees C for 12 hour, followed by drying the liquid at 80 degrees C for 12 hour to obtain the hybridized film.