NOVELTY - A biological oil hydrogenating method involves utilizing hydrogenation catalyst and biological oil as raw material. The biological oil and hydrogen are passed through first-stage hydrogenation reaction zone comprising two hydrogenation reactors under hydrogenation operation conditions. The raw oil and hydrogen are passed through one reactor operated at low temperature and another reactor operated at high temperature to obtain hydrogenation effluent-I followed by separating gas phase-I and liquid phase-I from the hydrogenation effluent-I.    USE - Method for hydrogenating biological oil for producing low-condensation point motor fuel.    ADVANTAGE - The method enables hydrogenating biological oil with improved activity stability of the catalyst.    DETAILED DESCRIPTION - A biological oil hydrogenating method involves utilizing hydrogenation catalyst and biological oil as raw material. The biological oil and hydrogen are passed through first-stage hydrogenation reaction zone comprising two hydrogenation reactors under hydrogenation operation conditions. The raw oil and hydrogen are passed through one reactor operated at low temperature and another reactor operated at high temperature to obtain hydrogenation effluent-I followed by separating gas phase-I and liquid phase-I from the hydrogenation effluent-I. The gas phase-I is recycled to the first-stage hydrogenation reaction zone. The liquid phase-I is transferred with recycle gas to second-stage hydrogenation reaction zone comprising hydroupgrading catalyst and hydrogenation modification catalyst to obtain hydrogenation effluent-II followed by separating gas phase-II and liquid phase-II from the hydrogenation effluent-II. The gas phase-II is recycled to the second-stage hydrogenation reaction zone. The liquid phase-II is transferred to a fractionating tower to obtain naphtha and low freezing point diesel oil followed by utilizing sulfur-containing material as reactant to maintain hydrogen sulfide content in the recycle gas, where the hydrogenation catalyst and hydrogenation modification catalyst comprises active component comprising tungsten, molybdenum, nickel and cobalt in a vulcanized state.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view illustrating a method for hydrogenating biological oil. '(Drawing includes non-English language text)'