The invention relates to a method for extracting synanthrin from jerusalem artichoke. The method includes the technologies such as pretreatment of jerusalem artichoke, lixiviation by hot water, concentration of filtrate, ethanol settlement, forming and the like. Based on ethanol settlement and forming, synanthrin is produced from jerusalem artichoke; except water and ethanol, no other substance is added; few materials are consumed and less pollution is caused; the method has few operation steps, low cost and a simple technology; and the obtained synanthrin product is low in monosaccharide content and sucrose content.