The invention relates to a preparation method of color printing ink solvent oil. The color printing ink solvent oil is prepared by utilizing naphthenic base crude oil fractions, adopting a special dearomatization process and a clay decoloring and refining process to produce base oil and adding proportioned unique compound additive, i.e. the solvent-refining process and the clay decoloring and refining process are carried out to the base oil which is then proportioned by a complex additive to finally prepare finished oil. The method does not generate aromatic toxicity and lessens damage to human beings; the color printing ink solvent oil keeps balance between the dissolving capacity and the release property of resin, solves the problems of unstable product indexes, such as water resistance,penetrability, and the like and has good printing performance, printing stability and storage stability of printing ink, light colors, good water resistance, strong penetrability, suitable aniline point, balanced dissolving capacity and release property to resin, no pungent odor and environmental protection. A printing ink product manufactured by the product has good printing quality, thick printing layer, uniform and full colors, bright colors and luster and strong printability.