Optical fiber factice extending oil and preparation method thereof

The invention relates to a preparation method for optical fiber factice extending oil. Pressure reduction distillate oil with the distillation range of 370-580 DEG C or solvent deasphalting oil with the distillation range of 480-580 DEG C in paraffin base crude oil is used as a raw material; under the hydrogen pressure of 15.0-20.0 MPa, the optical fiber factice extending oil with low pour point, and ultraviolet light thermal stability resistance is prepared through a three-section high-pressure hydrogenation combined technology of high-pressure hydroprocessing, isomerizing pour point depression and supplementing rectification. According to the optical fiber factice extending oil obtained through the combined technology, the initial Saybolt color is no less than +30, the ultraviolet light stability is no less than +25, the thermal stability is no less than +25, the PCA content is smaller than 1%, and the pour point is lower than -30 DE C, mostly close to -40 DEG C.