Total flavonoids were extracted from Hemerocallis citrina Baroni(H. citrina) in Qidong County of Hunan Province by ultrasonic and cyclodextrin aqueous solution. On the basis of single factor experiment， response surface design method was used to optimize the extraction process. The total yield of flavonoids and the antioxidant effect of the extracts with and without cyclodextrin were compared under optimal conditions. The results indicate that the optimal process for the extraction of total flavonoids from H. citrina with ultrasound-assisted cyclodextrin in aqueous solution is: the amount of cyclodextrin added was 26 mg/mL， the liquid-solid ratio was 31∶1 (mL/g) and the ultrasonic power was 490 W. The total flavonoid content of the extraction under these conditions was(9.26±0.07) mg/g， which was similar to the predicted value (9.28 mg/g)， showed that the optimized extraction process was stable， reliable， practicable and repeatable. Compared with extracted by water， the extraction rate of total flavonoids increased from 0.791% to 0.926% after cyclodextrin was added. Meanwhile， the in vitro antioxidant tests (FRAP， ABTS， DPPH) of the latter showed superior in vitro antioxidant activity. Therefore， the cyclodextrin-assisted extraction of total flavonoids is an effective extraction technology that is easy to operate and environmentally friendly.