Objective: To improve the quality standard of Mengyao Senden Siwei Soup. Methods: The microscopic identification of wenguan wood, chebula, gardenia and kawakuem seed in Senden four-flavor soup was established. Thin layer chromatography (TLC) was used to qualitatively identify wenguan wood, gardenia and chebula. The content of epicatechin in Junyao Wenguan wood was determined by high-performance liquid chromatography (HPLC) under the conditions of Supersil ODS-BP column (250 mm×4.6 mm, 5 μm), column temperature of 30 ℃, acetonitrile-1% formic acid solution (10∶90) as mobile phase, 280 nm as the detection wavelength, and the flow rate was 1.0 mL/min. Results: The microscopic characteristics of wenguan wood, gardenia, kawakuem seed and chebula were obvious. Thin-layer chromatography was used to analyze the results of wenguan wood, gardenia, kawakuem seed and chebula, and the results showed that the spots of each component were well separated and the negative control was not disturbed. The quantitative analysis of epicatein showed that the linear relationship was good in the concentration range of 0.018 7-0.138 8 mg/mL, and the regression equation could be expressed as Y=7E+06X-11 135 (correlation coefficient R²=0.999 3). The results of methodological validation showed that the average recovery rate of the sample recovery test was 98.17%, and the relative standard deviation was 1.73%. In addition, the RSDs of precision, repeatability and stability tests were controlled within the range of 0.11%, 1.75% and 1.55%, respectively, indicating that the method was reliable and stable. Conclusion: The method constructed in this study is accurate, reliable, sensitive and reproducible, and can be used for the quality control of Mongolian medicine Senden Siwei decoction.