The present invention provides a method for preparing 9,9-bis(3,4-dicarboxyphenyl)
fluorene anhydride, comprising the following steps: S1: adding
fluorenone and N-alkylphthalimide to a
solvent to obtain a
mixed solution; S2: heating the
mixed solution to a certain temperature, and dropping a catalyst acid, and stirring to heat the
raw material reaction in the
mixed solution to complete, to obtain a reaction solution; S3: adding the reaction solution to
ice water, continuing the temperature reaction for a period of time, cooling, adding water, filtering, washing the
filter cake with water, alkali washing, beating the
solvent, filtering, and high-temperature
vacuum drying to obtain 9,9-bis(3,4-dicarboxyphenyl)
fluorene anhydride. A method for preparing 9,9-bis(3,4-dicarboxyphenyl)
fluorene anhydride according to the present invention, the preparation method according to the present invention is simple and fast, simple to operate, high in yield, and has the advantages of high purity of finished product.