The invention relates to a hydrofining method for solvent oil and particularly relates to the hydrofining method for ink solvent oil. The hydrofining method for the solvent oil comprises the following steps of carrying out raw material pretreatment, carrying out first-time hydrofining, carrying out second-time hydrofining and carrying out precise fraction cutting. According to the method, a mixture of shale oil and coal tar is selected as a raw material, and heavy-oil components in the mixed oil product are fully and thoroughly cracked and are converted into light-oil products by using a two-step-progressive-cracking and suspended-bed slurry-bed double-reaction-bed hydrogenation process; meanwhile, impurities such as oxygen, sulfur, nitrogen, metal and the like in the mixed oil product can achieve the partial removal of alkene and arene compounds so as to saturate the mixed oil product, thus, the quality of intermediates is improved, the heat and light stability of final products is improved, and the defects that aliphatic ink solvents are poor in dissolving power and aromatic-hydrocarbon ink solvents are high in toxicity are overcome; and the harm to environment and human caused by ink during use is lowered, so that the solvent oil is extensively applicable to offset-printing and letterpress-printing ink.