Abstract: In the study,absorption maximum wavelength of 510 nm was used as index for the orthogonal design mode to screen the optimization parameter of rutin extraction from Sophora japonica,extracted rutin was used for super oxide anion radical method for antioxidant activity experiments.The results showed that alcohol extraction was the most ideal method,and its parameters was ethanol concentration of 80%,ethanol volume of 100 mL and ultrasound temperature of 45℃,rutin of 11.6% could be achieved by it.There was dose-dependant relation for rutin to clean up free radicle O2-·,and the scavenging index of IC50 was 0.030 5 g/L,which is significant differences exist（t=2.93,P0.05）.