Direct liquefaction process of coal mixed with medium and low temperature coal tar

The invention discloses a direct liquefaction process of coal mixed with medium and low temperature coal tar. The process comprises the following steps: carrying out purification treatment on the medium and low temperature coal tar, carrying out vacuum distillation or atmospheric distillation on the medium and low temperature coal tar subjected to purification treatment, and cutting the factions into heavy oil fractions and light oil fractions, wherein the temperature range of the cut point is 320-380 DEG C; subjecting a coal oil mixture obtained by mixing pulverized coal with the heavy oil fractions higher than the cut point, hydrogen and a catalyst to reaction in a primary reactor at a reaction temperature of 420-460 DEG C, sending a primary reaction product to the upper part of a secondary reactor, enabling a gas phase component in the primary reaction product to flow out from the top of the secondary reactor, enabling solid and liquid components in the primary reaction product to flow down in the secondary reactor to carry out countercurrent contact reaction with hydrogen flowing up at a reaction temperature of 430-480 DEG C, and carrying out fractional distillation after the reaction ends. The process has the effects of obviously improving the production efficiency of direct coal liquefaction, increasing the conversion rate of pulverized coal and improving the quality of naphtha and diesel products, and is suitable for the large-scale direct coal liquefaction industry.