Abstract: Objective: To obtain conditions for extracting flavonoids from Tenebrio molitor. Methods: Flavonoids was extracted from Tenebrio molitor with distilled water under the assistance of ultrasonic. On the basis of one-factor-at-a-time investigations, Box-Behnken experimental design was used to provide experimental data for establishing a regression model describing the yield of flavonoids, and response surface methodology was employed to analyze the pairwise interactive effects of liquid-to-solid ratio, extraction time, extraction temperature and ultrasonic power. Results: Liquid-to-solid ratio of 18.34:1(mL/g), extraction time of 30.06min, extraction temperature of 58.43℃, and ultrasonic power of 380.62W. Under the optimal extraction conditions, the actual yield of flavonoids was 11.47mg/g, which was in basic agreement with the theoretical value of 11.58mg/g. Conclusion: The optimization of the actual conditions and the theoretical prediction fitting degree is high.