NOVELTY - A hybrid membrane comprises sulfonated polyether ether ketone with amino acid group of organic chromium framework. The thickness of the membrane is 55-80 microns. The particle diameter of the sulfonated polyether ether ketone with amino acid group of organic chromium framework is 500 nm. The mass ratio of the sulfonated polyether ether ketone with sulfonated polyether ether ketone is (0.60-0.90):(0.40-0.10). The sulfonating degree of the sulfonated polyether ether ketone is 45-75%.    USE - Hybrid membrane for separating carbon dioxide-acetylene gas.    ADVANTAGE - The hybrid membrane contains easily available raw materials, and has high selectivity coefficient of 35-72 and permeability of 977-2490 barrer.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing an above-mentioned hybrid membrane, which involves preparing organic chromium framework, preparing amino acid group with organic chromium framework and preparing sulfonated polyether ether ketone with amino acid group of organic chromium framework. The organic chromium framework is prepared by mixing chromium nitrate nonahydrate, terephthalic acid and hydrofluoric acid in molar ratio of 1:1:1 to obtain 0.8-1.2 mass% aqueous solution, transferring the solution to a reaction kettle, stirring the mixture for 10-60 minutes, reacting the mixture at 180-240 degrees C for 6-24 hours, filtering the mixture to obtain crystals A, refluxing the crystals A with N,N'-dimethylformamide at 80-150 degrees C, washing the crystals A, exchanging remaining crystals with ethanol at 50-100 degrees C, adding the crystals A in drying box at 150 degrees C for 24 hours, and removing crystals A from residual ethanol molecules to obtain a pure organic chromium framework with particle diameter of 500 nm. The amino acid group-organic chromium framework is prepared by drying the organic chromium framework at 160 degrees C for 24 hours, removing water molecules from the organic chromium framework, degassing the framework under vacuum at 110 degrees C for 1 hour, reacting the organic chromium framework with polyethylene imine at 60 degrees C, stirring the mixture for 2-12 hours, centrifuging the mixture, washing with water and then with anhydrous ethanol, placing the mixture in vacuum drying box, and drying the mixture at 35-60 degrees C for 48 hours to obtain amino acid group with organic chromium framework with particle diameter of 500 nm. The molecular weight of the polyethylene imine is 300. The mass ratio of the organic chromium framework and polyethylene imine is 1:(0.2-5). The sulfonated polyether ether ketone with amino acid group of organic chromium framework is prepared by adding sulfonated polyether ether ketone to 5-15 mass% N,N'-dimethylformamide, stirring the mixture, adding the prepared amino acid group with organic chromium framework to the mixture, dispersing the mixture ultrasonically for 4-18 hours, stirring the mixture for 24 hours, maintaining the mixture for 1-5 hours, de-foaming the mixture to obtain casting liquid, pouring the casting liquid on a glass dish, drying the glass dish at 60 degrees C for 12 hours and drying the glass dish at 80 degrees C for 12 hours to obtain the hybrid membrane.