The invention provides a coal liquefaction method and device. The coal liquefaction method comprises the steps as follows: first liquefaction reaction is carried out on coal slurry and hydrogen to obtain a first liquefied product, wherein the first liquefied product comprises a first gas mixture and a first heavy product and the first gas mixture comprises a first liquefied light oil and a first gas product; a first heavy product in the first liquefied product is separated and second liquefaction reaction is carried out on the first heavy product and the hydrogen to obtain a second liquefied product; and before or during the second liquefaction reaction, the method also comprises the step of adding a first hydrogenation catalyst to the first heavy product. Through the method and the device provided by the invention, the conversion rate and the oil yield of coal can be improved, and meanwhile, the hydrogen consumption and the gas yield are reduced.