NOVELTY - Preparation of polyvinylidene fluoride grafted and blended poly 2-acrylamide-2-methylpropanesulfonic acid proton exchange film, comprises: (a) dissolving sodium orthosilicate in N-methylpyrrolidone solution; (b) pouring 53-72 wt.% of polyvinylidene fluoride; (c) weighing 1-2 wt.% of ammonium persulfate and 20-30 wt.% of 2-acrylamide-2-methylpropanesulfonic acid, continuously performing electric agitation; (d) casting the solution to clean glass plate, evaporating, drying and removing film; and (e) extracting.    USE - The process is useful for preparing polyvinylidene fluoride grafted and blended poly 2-acrylamide-2-methylpropanesulfonic acid proton exchange film (claimed).    ADVANTAGE - In utilizing the process, the proton exchange film has better proton electricity-conducting device, and is convenient for achieving large-scale production.    DETAILED DESCRIPTION - Preparation of polyvinylidene fluoride grafted and blended poly 2-acrylamide-2-methylpropanesulfonic acid proton exchange film, comprises: (a) dissolving sodium orthosilicate with concentration of 5-12 wt.% in N-methylpyrrolidone solution containing 3-5 wt.% of water, and agitating for 1-3 hours to obtain solution A; where each gram of polyvinylidene fluoride needs 5-6 ml of liquid N-methylpyrrolidone; (b) pouring 53-72 wt.% of polyvinylidene fluoride (PVDF) to solution A to agitate for 1-2 hours to obtain a mixed solution B; (c) weighing 1-2 wt.% of ammonium persulfate and 20-30 wt.% of 2-acrylamide-2-methylpropanesulfonic acid (AMPS) to add in the mixed solution B, continuously performing electric agitation for 1-2 hours in water bath of 80-90 degrees C, and letting it stand for 3 hours to obtain solution C; (d) casting the solution C to clean glass plate, controlling thickness of the casting film as 0.08-0.1 mm, evaporating for 5-7 hours at 80-90 degrees C, drying and removing film to obtain graft copolymerized film of modified polyvinylidene and poly 2-acrylamide-2-methylpropanesulfonic acid; and (e) extracting the obtained film with deionized water for more than 24 hours to completely remove 2-acrylamide-2-methylpropanesulfonic acid homopolymer.