Polymer fatliquoring agent containing sulfite structure and preparation method thereof

The invention discloses a polymer fatliquoring agent containing a sulfite structure and a preparation method thereof. The preparation method specifically comprises the following steps of enabling polyglycerol and maleic anhydride to carry out esterification reaction, so as to prepare an intermediate A containing active carboxyl; further performing esterification reaction on the intermediate A and long-chain fatty alcohol, so as to prepare an intermediate B; performing sulfitation reaction on the intermediate B and sulfite, so as to obtain the polymer fatliquoring agent containing the sulfite structure. The polymer fatliquoring agent containing the sulfite structure has the advantages that the synthesis technology is simple and environment-friendly, the organic solvent is not used, and the toxic or harmful matter is not produced in the synthesizing process; the good fatliquoring effect, filling property, electrolyte-resistant stability and organic solvent extraction-resistant property are realized, and the content of COD (chemical oxygen demand) in fatliquoring waste liquid is reduced.