The effects on the yield of total flavonoids were studied by reference enzyme dosage, pH value, ratio of material to liquid, ethanol concentration, enzymolysis temperature and time. A 4 factor with 3 horizontal response surface test optimization were conducted. The optimal extraction conditions of the total flavonoids of dandelion were as follows: 122 (g/mL), pH 4.5, 52% ethanol concentr-ation, the hydrolysis temperature was 51 ℃. Under these condi-tions, the yield of total flavonoids was 15.09 mg/g. The results of in vitro functional experiments showed that the total flavonoids extract of dandelion had strong antioxidant activity and scavenging ability against free radicals.