Coal tar slurry bed and fixed bed series connection hydrogenation process

The present invention provides a coal tar slurry bed and fixed bed series connection hydrogenation process, which comprises: (1) carrying out a purification treatment; (2) carrying out pressure reducing or normal pressure distillation on the purified coal tar, and cutting into the light oil distillate and the heavy oil distillate, wherein the cutting point of the light-heavy oil distillate is 220-370 DEG C; (3) mixing the light oil distillate and H2, uniformly mixing, conveying the obtained material into a fixed bed, and carrying out hydrorefining under the hydrorefining catalyst effect to prepare a hydrorefining product; and (4) mixing the heavy oil distillate, a hydrocracking catalyst and H2, uniformly mixing, sequentially conveying the obtained material into a first-stage slurry bed and a second-stage slurry bed to carry out a double-stage hydrocracking reaction, and carrying out a fractionation treatment on the prepared hydrocracking product, wherein the distillate with the boiling point of more than 540 DEG C is externally discharged, the distillate with the boiling point of less than 350 DEG C is recycled as part of the fed material of the fixed bed, and the remaining components return to the first-stage slurry bed inlet. With the method of the present invention, the sulfur content and the nitrogen content in naphtha and diesel fuel are reduced, and the cetane number in the diesel fuel is substantially improved.