Using coal tar distillate as the starting material, a novel high-purity 2,6-naphthalenedicarboxylic acid (2,6-NDA) preparation method was developed. Firstly, the 2,6-dimethylnaphthalene (2,6-DMN) precursor was separated by successive vacuum distillation, melt crystallization, and solvent crystallization from the 250-270 degrees C fraction of the coal tar distillate. Then, over Co-Mn-Br as catalysts, oxidation of 2,6-DMN was carried out in acetic acid to produce crude 2,6-NDA with molecular oxygen. By high-temperature hydrogenation, the crude 2,6-NDA was further purified to obtain high-purity 2,6-NDA. From the coal tar distillate to pure 2,6-NDA, the operation parameters and reaction conditions of each process were optimized and evaluated, indicating that the proposed 2,6-NDA synthesis method has great potential for industrial application to create cheap feedstock in viable yields.