In order to study the optimum ultrasonic-assisted extraction technology of flavonoids in hawthorn juice under pectinase treatment, the single-factor tests and orthogonal array design were employed to optimize the extraction conditions. The effects of boiling treatment time, ultrasonic extraction time, ultrasonic extraction temperature and ultrasonic power on the content of flavonoids in hawthorn juice were researched. And the hawthorn flavoinoid extraction conditions were optimized as follows: boiling treatment time 30 min, ultrasonic extract time 50 min, ultrasonic extract temperature 50 ℃ and ultrasonic power 150 W. Under the optimized extraction conditions, the content of flavonoids was 335.32 mg/100 mL. Ultrasonic extraction process remarkably decreased the extraction time than shaking extraction.