The invention discloses a chemical total-synthesis preparation method for prostratin. The chemical total-synthesis preparation method is characterized in that an easily prepared 5-(hydroxymethyl)-2-cyclopentene-1-alcohol is taken as a raw material, light oxidization de-arylation reaction is performed, addition is induced in molecules, olefin double decomposition reaction is performed, and a targetproduct is finally obtained through functional group conversion. The preparation method is simple and convenient in operation, and is gentle in condition, and the synthesized products are consistentwith spectral data of natural products.