Coal tar pitch (CTP) is abundant in aromatic ring structures, which would facilitate preparing high added value benzene polycarboxylic acids (BCAs) by oxygen-depolymerization of CTP. However, during the preparation of BCAs by alkal-O2 oxidation of CTP, part of CTP is bonded to the inner wall and bottom of the reactor, which hinders CTP further oxidation. Extraction with CH3OH and air oxidation were used in CTP pretreatment, and the influence of pretreatment methods was explored on the preparation of BCAs by alkali-O2 oxidation of CTP. Some light components of CTP could be removed after extraction, reducing adhesion between CTP and the reactor. Then, the extraction residue of CTP with CH3OH was further pre-oxidized by air, which introduced the oxygen-containing functional groups, thus increasing the collision between extraction residue and aqueous alkali. In the resulting water soluble acids from oxidation of the pre-treated CTP, the selectivity of BCAs can reach 80%. Furthermore, the relative content of benzenepentacarboxylic acid and mellitic acid in BCAs could increase up to 24%.