89.87%。In order to improve the extraction effect of flavonoids from Lycium barbarum L., ultrasonic was used to extract flavonoids of Lycium barbarum L. Through single fraction experiments and orthogonal experiments, the optimal technological parameters were determined. The result expresses the optimal technological parameters are the concentration of ethanol 80%, liquid to solid ratio 50mL/g, ratio of ultrasonic run and interim time 3s/1s, ultrasonic power 500W, extracting 50min, the extraction rate was 89.87%.