Abstract: The trimethyl quaternary ammonium salt was synthesized under microwave irradiation with wheatalkalilignin as raw material, which was extracted from black liquor from the kraft process. Its dispersibility and flocculability were determined: surface tension decreased with the increasing concentration of trimethyl quaternary ammonium salt, degreasing of surface tension was less effective toward water, the surface tension was 63.64 mN/m with its concentration of 500 mg/L;it had a certain dispersion of calcium carbonate particles and can be used as a scale inhibitor; the flocculation of trimethy quaternary ammonium salt was examined by the acid dye of Acid Red B and Acid Orange GG, and the results showed that the acid dye of Acid Red B and Acid Orange GG could be flocculated, and decolorization of Acid Orange GG was higher; the trimethyl quaternary ammonium salt had sedimentation of flocculation with a concentration of 1 000 mg/L kaolin colloidal particle at a concentration of 300-500 mg/L with pH values of no more than 3.