To optimize the extraction process of Galla Chinensis tannin,and to provide a reference for the preparation of compound Zhixue Xiaoyan ointment.Methods：HPLC method for the analysis of gallic acid was established.The chromatographic conditions were as follows：mobile phase：methanol：acetonitrile：0.2% phosphate 4:11:85; column temperature：30 ℃; detection wavelength：273 nm; flow rate：1 mL/min,injection amount：10 μL.Then,the extraction rate of gallic acid was taken as the index,the extraction times were fixed on the basis of single factor investigation,and the orthogonal experiment was carried out to optimize the extraction process of total tannin by orthogonal test with water dosage,extraction time and extraction temperature as factors.The L9(34）orthogonal table was used to carry out the orthogonal test to optimize the extraction process of total tannin.Results：The precision,repeatability and stability of the HPLC method were all in line with the requirements of pharmacopoeia.The linear relationship between the concentration of gallic acid in the range of 2.34~300 μg and the peak area was good.The regression equation was Y=29.955X+9.6352,the correlation coefficient r=1,and the average recovery rate was 101.88%.The optimum extraction process of tannin by orthogonal test was A3B1C3,that is,in 80 ℃ water bath,12 times of water was used as solvent to extract tannin twice for 1.5 hours each time.Conclusion：The HPLC method established in this paper is accurate and stable,and can be used for the determination of gallic acid,and the optimum extraction process of Galla Chinensis by orthogonal test is stable and reliable,which is suitable for the extraction of total tannins.