The utilization of lignin as a dispersant and protective agent for pesticide is a promising strategy for its high-value application, however, its use is limited by the poor solubility of lignin. In this study, the solubility and antioxidant performance of lignin were enhanced by treating it with Fenton's reagent and sulfomethylation reaction. The product has a sulfur content of up to 6.57 % and a DPPH radical scavenging capacity of up to 70 %. The resulting product, sulfomethylated lignin (SFKL) exhibited excellent antioxidant and dispersant properties for emamectin benzoate (EB). The samples containing sulfomethylated lignin exhibited smaller particle sizes and higher suspension rates after accelerated thermal storage than the samples containing commercially available lignosulfonate (SL). The average particle size of the sample using the best sample SFKL