Abstract: This research regarded quercetin as contrast caliber, determine content of total flavonoids in pomegranate husk in Pierman by spectrophotometry. Random-centroid optimization(RCO) methodology was used to optimize the ultrasonic extraction technology. Four factors,including ethanol concentration,liquid solid ration, temperature, extraction times were investigated. The optimum extraction process of flavonoids from pomegranate by RCO had been established as follows:ethanol concentration 87%,extraction time 37 min,the extraction temperature 59 ℃,solid-liquid ratio 1∶24(g/m L). The yield of flavonoids was 25.56%. Extraction yield of the total flavonoids of pomegranate husk had a downward trend,with the increase of extraction temperature and ethanol concentration,this was showed that the polarity was larger of flavonoids from pomegranate husk.When the total flavonoids concentration was 12 mg/m L,its ability of scavenging the hydroxyl radical reached the highest,and the clearance rate was 91.6%.