TECHNOLOGY FOCUS - POLYMERS - Preparation (claimed): Preparing the block copolymer of side-chain sulfonated polyimide and sulfonated polybutadiene where the materials are counted by mass parts comprises: (a) dissolving 1-10 parts of carboxyl-terminated polybutadiene into 30-50 parts of toluene, adding 1-10 parts of thionyl dichloride, and agitating evenly; under the protection of nitrogen, heating up to 60-80 degrees C, after reacting for 1-3 hours, heating up to 90-110 degrees C, continuing reacting for 10-20 hours; after finishing reaction, cooling, decompressing and distilling to remove the residual thionyl dichloride, obtaining the toluene solution of acyl chloride-terminated polybutadiene; (b) adding 10-35 parts of 3,5-dinitrobenzoyl chloride and 5-30 parts of anhydrous aluminum trichloride into the three-neck round flask, slowing agitating under ice bath; after slowly dripping 5-30 parts of diphenyl ether in 1-2 hours, reacting for 30-90 minutes; and then heating to 50-70 degrees C under the protection of nitrogen, continuing reacting for 12-24 hours; cooling the reaction solution, pouring into glacial hydrochloric acid solution to settle and agitate, after filtering, washing the rough product by water, after vacuum drying, obtaining 3,5-dinitro-4'-phenoxy benzophenone; (c) adding 3-12 parts of 3,5-dinitro-4'-phenoxy benzophenone, 0-0.5 parts of palladium carbon and 40-80 parts of alcohol solvent into the three-neck round flask, agitating evenly, heating into circumfluence under the protection of nitrogen; slowly dripping mixed solution of 3-15 parts of hydrate hydrazine and 5-20 parts of alcohol solvent in 6-12 hours, continuing refluxing for 12-24 hours; cooling the reaction solution, pouring the reaction solution into large number of deionized water to settle, filtering to obtain light yellow rough product; after vacuum drying, obtaining 3,5-diamino-4'-phenoxy benzophenone; (d) adding 1-5 parts of 3,5-diamino-4'-phenoxy benzophenone into the round flask in the ice bath, slowly dripping 20-40 parts of concentrated sulfuric acid; after agitating the solids into dissolving completely, heating into 60-80 degrees C and reacting for 6-10 hours; cooling the reaction solution, slowly pouring the reaction solution into 100 parts of ice water mixture, obtaining large number of white settlement; dissolving the settlement obtained by filtering into sodium hydroxide (NaOH) solution, filtering to remove impurity, dripping the concentrated hydrochloric acid into transparent filtrate until the settlement is produced again; after filtering, repeatedly washing the settlement by deionized water and alcohol solvent, after vacuum drying, obtaining sulfonated 3,5-diamino-4'-phenoxy benzophenone; (e) adding 0.5-2.5 parts of sulfonated 3,5-diamino-4'-phenoxy benzophenone and 0.3-1.5 parts of tri-ethylamine into 30 parts of metacresol to agitate, after dissolving the solid completely, adding 0.5-2 parts of 1,4,5,8-naphthalene tetracarboxylic dianhydride and 0.5-2 parts of benzoic acid; under the protection of nitrogen, heating up to 80-100 degrees C, after reacting for 2-4 hours, heating up to 180-190 degrees C and reacting for 16-20 hours; cooling the reaction solution, pouring it into 200 parts of acetone to adequately agitate, after filtering, washing the rough product for three times by 50 parts of acetone, after vacuum drying, obtaining amino-terminated side-chain sulfonated polyimide; (f) adding 1-4 parts of amino-terminated side-chain sulfonated polyimide and 0.1-1 parts of tri-ethylamine into 20-40 parts of mixed organic solvent, after completely dissolving the solid, adding 2-8 parts of toluene solution of acyl chloride-terminated polybutadiene drop by drop; reacting for 6-18 hours at 50-70 degrees C, cooling the reaction solution, pouring into 200 parts of acetone to settle; after filtering, washing the settlement by deionized water and acetone in turn, vacuum drying, obtaining the block copolymer of side-chain sulfonated polyimide and sulfonated polybutadiene, where the mixed organic solvent is dimethyl sulfoxide solution of N-methyl-2-pyrrolidone with a mass concentration of 50-70%; (g) under ice bath condition, dripping 15-20 parts of concentrated sulfuric acid into 15-20 parts of acetic anhydride, continuously agitating, reacting for 6-12 hours, obtaining acetyl sulfonate; and (h) dissolving 1-2 parts of block copolymer of side-chain sulfonated polyimide and sulfonated polybutadiene into 30 parts of dimethyl sulfoxide, after agitating evenly, adding 1-5 parts of acetyl sulfonate drop by drop; under the protection of nitrogen, heating to 70-100 degrees C and reacting for 9-18 hours, after finishing reaction, pouring the mixed solution into 200 parts of alcohol solvent, adding NaOH to adjust solution into neutrality; after filtering, washing the rough product with 50 parts of alcohol solvent, and then washing by deionized water; finally vacuum drying the rough product to obtain the block copolymer of side-chain sulfonated polyimide and sulfonated polybutadiene. The structural formula of the carboxyl-terminated polybutadiene is represented by Formula (II). The alcohol solvent is methanol or ethanol.p=50-80.