The asparagus of Triarrhena lutarioriparia (TL)is a popular vegetable with abundant chemical compoundsin China. This study aims to optimize the ultrasound-assistedextraction (UAE) method for its content of totalflavonoid and antioxidant activities by response surfacemethodology (RSM). Box-Behnken design was adopted toevaluate the influences of ethanol concentration, extractiontime and solvent-to-sample ratio on the extraction yield oftotal flavonoid and the antioxidant activity. Considering themaximum content of extracted total flavonoids andantioxidant activity, the optimal extraction conditions wereacquired with 70% (v/v) ethanol by UAE for 60 min at asolvent-to-sample ratio of 40 mL/g. The proportion of theextraction of total flavonoid was 15.88 mg/g and antioxidantactivity reached 79.53%. The RSM would be recommendedas an appropriate model for simultaneousoptimization of the UAE conditions for the content of totalflavonoid and the antioxidant activity of asparagus of TL.