Abstract: Summarize the composition,characteristics and research progress of coal tar.The most widely used coal tar chemical products such as naphthalene,phenolic compound,pyridinium could be prepared from the wash oil of coal tar.The products has high quality.The technological process is that,through vacuum distillation,first gather the fraction at different extraction temperature ranges,then dephenolize,distill,crystallize and extract.Study separation and purification methods of fluorene,benzpyrole and biphenyl.The preparation of fuel oil from coal tar by catalytic hydrogenation is the development direction of coal tar deep processing,which could reduce the pollution caused by coke oven gas combustion.