Preparation method and application of modification polyanion sorption agent

The invention discloses a preparation method of a modification polyanion sorption agent. The preparation method provided by the invention comprises the following steps of: adding paratoluenesulfonic acid in a 4-6 mol/L hydrochloric acid solution, and uniformly stirring so as to form a mixed solution; adding an aniline monomer in the paratoluenesulfonic acid the quality of which is 0.5-2 times, and stirring for 2-5 hours; then adding an initiating agent ammonium persulfate the quality of which is 2-5 times in the aniline monomer, and continuously stirring for 2-5 hours; and pumping filter, laundering a solid to deposit, drying and grinding, thus obtaining the modification polyanion sorption agent. The preparation method provided by the invention can be used for realizing hydrochloric acid and paratoluenesulfonic acid to modify the polyaniline, an inner porthole structure of a polymer is changed, and the adsorptive property and heat stability of the polyanion are strengthened; meanwhile, the adsorptive surface