The invention relates to a preparation method of ramelteon intermediates, the preparation method comprises the following steps: adding diethyl cyanomethylphosphonate into an organic solvent, mixing, adding an alkali in batches, dropping a solution of compounds I for reaction, extracting, washing and drying, thus obtaining a compound II; adding an organic solvent, aluminum chloride and lithium aluminium hydride into a reaction vessel, dropping a solution of the compound II, first reacting at a low temperature, then reacting at the room temperature, adjusting the pH of the reaction solution to 8-9, filtering, drying a filter liquor to obtain a solid compound, dissolving the solid compound in dichloromethane (DCM), then adding HCl / EtOH, adjusting the pH to be acidic, filtering and drying to obtain a compound III, and thus respectively obtaining a compound IV, a compound V and a compound VI by high pressure hydrogenation under the effects of different catalysts. The preparation method has the advantages of simple process, high yield, low cost and high purity of target products, and is conducive to the mass production of a ramelteon key intermediate.