Abstract: o-Veratraldehyde is an important pharmaceutical intermediate.With common synthetic methods taken into consideration,veratraldehyde was prepared by using guaiacol as the starting material and conducting a series of phenolic hydroxyl allylation,Claisen rearrangement,phenolic hydroxy methyl etherification,Triton B-catalyzed olefin isomerization and ozonation/reduction reactions.The total yield of this 5-step reactions was 54%.The above-mentioned synthesis method only requires raw materials that are low-cost and easily acquired,its relative reaction conditions are mild and the work-up is simple,thus it may provide certain value in the industrial applications.