add appropriate amount of solvent toluene into the reaction kettle, add span 60 and acrylic acid (mol ratio is 1.1: 1) in turn, then add p-toluenesulfonic acid in the amount of catalyst and appropriate polymerization inhibitor. The temperature is heated under stirring, and the reflux is 15 h until the anhydrous separation reaction is stopped. Neutralize with NaOH, after the water layer is separated, the oil layer is distilled under reduced pressure, and the solvent is distilled to obtain the crude product. Recrystallized with ethyl acetate and dried in vacuum to obtain fine products.