The present invention relates to a method for preparing a tricyclic derivative, and more particulary, to a method for preparing a tricyclic derivative inetermediate with high yield and purity, the method including: introducing a hydroxy group by esterifying and substituting 2-fluoroisophthalic acid compound； introducing a piperidyl group； introducing a hydroxy group through reduction reaction； and then hydrolyzing the resultant compound, and to a method for preparing the tricyclic derivative using said intermediate. According to the method of the present invention, it is possible to provide a tricyclic derivative and an intermediate thereof with high productivity and economic feasibility as well as high purity and yield, by purifying a compound using re-crystallization unlike typical methods of using column chromatography. In addition, the method of the present invention can be usefully used for industrial mass production because sodium borohydride or lithium aluminum hydride with low risk of a fire is used unlike typical methods of using lithium borohydride which is not industrially applicable due to high risk of a fire.
