Taking the total flavonoids from Geum aleppicum by using ultrasound-assisted extraction and purification techniques, and test the scavenging ability to DPPH of total flavonoids. With extraction quantity of total flavonoids as dependent variable, the independent variables including ratio of liquid to solid, ethanol concentration, ultrasonic power, ultrasonic temperature and ultrasonic time were studied on extraction by single experiment and response surface methodology; the adsorption and desorption of total flavonoids were used to investigate adsorption and elution conditions of macroporous resin; the scavenging ability to DPPH was used to investigate antioxidant activity. The optimal extraction conditions were: ultrasonic power 300 W, ethanol concentration45%, the ratio of liquid to solid 161（mL/g）, extraction time 102 min, extraction temperature 73 ℃. Under the conditions, the extraction amount of flavonoids was 17.02 mg/g. AB-8 macroporous resin purification techniques conditions were: concentration of feed 0.5 g/mL, the ratio of diameter-height 1:6, the volume of polyphenols sample 20 mL (2 BV), elute ethanol concentration 40%, elute volume 60 mL (6 BV). After eluted with AB-8 resin, the retention rate of total flavonoids was 83.3%, the refined multiples was 4.5 times, the content of total flavonoids was 61%. The result of experiment on scavenging ability to DPPH showed that IC₅₀ value of purification was obviously less than that of extracts of total flavonoids, and a little higher than that of V_C, the scavenging order was V_C＜purification of total flavonoids＜extract of total flavonoids, and the IC₅₀ values of DPPH free radical scavenging was 57.4 μg/mL.