Abstract: Total flavonoids from Abelmoschus corolla were extracted by sodium dodecyl sulfate (SDS)-assisted ultrasonic wave, and its inhibition of xanthine oxidase (XOD) was studied, so as to achieve the efficient utilization of the resources of Abelmoschus manihot. Taking the content of total flavonoids as the index, the solid/liquid ratio, ultrasonic power and concentration of SDS were determined by single factor experiment. The extraction process of total flavonoids was optimized by combining Box-Behnken center and response surface analysis, and the effect of the extract on inhibiting XOD was determined. The results showed that the optimal extraction method was as follows: The solid/liquid ratio was 1:48 g/mL, the ultrasonic power was 320 W, the concentration of SDS was 0.05 g/mL. Under these conditions, the total flavonoids in Abelmoschus corolla were 4.63 mg/g. In the range of inhibitor concentration of 0.38~1.92 mg/mL, the inhibition rate of extracting solution was 98.35%, which had a good inhibitory effect on XOD.