Orthogonal array design was employed to optimize the ultrasonic extraction of Chinese Gallotannins(CGTs),and the purification process of CGTs was also studied in this paper.The optimal extraction condition of CGTs were as follows: ultrasonic power was 200 W,60% acetone as extractant,liquid-to-solid ratio is 24:1,extraction time was 30 min,temperature was 40℃;The maximum extraction efficiency obtained was 92.27% in two times extraction.The purification degree of CGTs was up to 92.89% with organic solvents.