Method for preparing diesel oil component or jet fuel component by using animal and plant oil

The invention provides a method for preparing a diesel oil component or jet fuel component by using animal and plant oil. The method comprises the following steps of: (1) dividing the animal and plant oil into at least two parts, introducing the at least two parts of animal and plant oil to a plurality of catalyst beds of a first hydrogenation reactor, and enabling the at least two parts of animal and plant oil and a hydrodeoxygenation catalyst to contact and react to obtain n-alkanes with the carbon number of 8-24; (2) filling an isomerization catalyst in a second hydrogenation reactor, introducing a reaction product obtained in the step (1) to the second hydrogenation reactor, and reducing a condensation point after isomerization reaction to obtain a diesel oil component; or, (3) filling a selective cracking catalyst in the second hydrogenation reactor, introducing the reaction product obtained in the step (1) to the second hydrogenation reactor, and then, carrying out selective hydrocracking and isomerization to obtain a jet fuel blending component. The method provided by the invention is high in jet fuel yield; and the prepared jet fuel blending component is good in quality and can be mixed with the traditional petroleum-based jet fuel according to any proportion so as to be an excellent blending component.