Objective:To optimize the extraction process of flavonoids from Artemisia argyi and evaluate the antioxidant activity in vitro. Methods:The ultrasonic-microwave combined water extraction method of Artemisia flavonoids was determined, and the extraction process was studied with the yield of total flavonoid, DPPH radical scavenging rate and ·OH radical scavenging rate of Artemisia argyi. Based on the single factor experiment, the factors with greater influence were screened through Plackett-Burman design, then optimized extraction process by response surface test. Results:The best extraction process was ultrasonic power 340 W, ultrasonic time 27 min, microwave power 600 W, microwave time 120 s, solid-liquid ratio 1∶30 (g/mL). Under these conditions, the yield of total flavonoids can reach 87.93 mg/g, DPPH radical scavenging rate is 80.84%, ·OH radical scavenging rate is 77.92%. Conclusion:The yield of flavonoids by this method is significantly better than the traditional boiling and water bath extraction (P＜0.05), and the antioxidant activity of Artemisia argy is better.