The present invention provides an application of higher fatty alcohol in the preparation of a formulation for improving the disease resistance and stress resistance of plants, and an application of a formulation containing higher fatty alcohol in improving the disease resistance and stress resistance of plants by improving the transcription level of a gene related to a metabolic pathway of phenylpropane, improving the transcription level of a gene related to a biosynthesis pathway of isoflavone and increasing the content of an isoflavone compound of plants.