The invention provides a method for extracting ethyl vanillate from peony. According to the method, peony petals are used as a raw material. Through heating reflux, an active component containing ethyl vanillate are extracted from peony petals; and through extraction, macroporous resin column chromatography, silica gel column chromatography and recrystallization, ethyl vanillate is obtained. By the method for extracting ethyl vanillate from peony, ethyl vanillate with high purity can be obtained, and the purity can reach 95% and above. During the extraction process of ethyl vanillate, medicines used in the process are all common medicines, and production cost is low. Meanwhile, organic solvents such as ethanol and macroporous resin in the chromatographic column can be repeatedly used. Thus, the environment is not polluted, and production cost is further reduced. The method of the invention is suitable for large-scale promotion and application. The ethyl vanillate obtained by the method has stronger activity than orlistat and can be applied in preparation of diet pills or a medicine with inhibitory effect on lipase activity.