The invention discloses a pronephrium megacuspe compound, a preparation method thereof and application. The invention provides a new chemical structural formula of pronephrium megacuspe compound, wherein the compound is made from plant pronephrium megacuspe with insecticidal activity, bactericidal activity and anticarcinogenic activity. The invention can be applied to preparing insecticide, bactericide and anticarcinogenic medicine. The invention finds out the active compound from the fern for the first time and provides an important technical base for researching mothproof and disease-resistant activities of the fern. The preparation method of the invention is simple and the manufacturing cost is low, so the preparation method is applied to industrial extension.