The present invention relates to a chemical synthesis method for phillyrin. The method of the present invention comprises: first dissolving a glycosyl acceptor, phillygenin and a glycosyl donor in an organic solvent and conducting glycosylation to obtain tetracylated phillyrin; then dissolving the tetracylated phillyrin in an organic solvent adding sodium methoxide to conduct deacylation, and then adding an acidic pH regulator to regulate the pH value of the reaction mixture to neutral; and finally conducting purification treatment. The preparation method of the present invention has the following progressiveness and practical value that the raw materials are easy to get, the catalyst for glycosylation is cheap and easy to get, the manufacturing cost is significantly reduced, and industrial production can be realized.