Objective To optimize supercritical extraction technique from four medicinal materials, which are the part components in the recipe of Keganliyan Oral Liquor and are extracted traditionally for essential oils. Methods Extraction ratio and menthol extraction quantity were taken as evaluated indexes. Supercritical extraction technique was researched with orthogonal tests, gas chromatography, and SAS statistic. Results Within the test levels, temperature and time showed evident effect on extraction ratio and menthol extraction quantity, while pressure did not show any evident effect on them、 The preferable technique to extraction ratio is temperature at 55 ℃, time for 120 min, and extracted pressure at 27 MPa; and the preferable technique to menthol extraction quantity is temperature at 45 ℃, time for 120 min, and extracted pressure at 22 MPa. Conclusion The optimized supercritical extraction technique for Keganliyan Oral Liquor is feasible.