The invention discloses a preparation method of a hydrocracking catalyst, comprising the following contents: 1, selecting the hydrocracking catalyst's carrier material which contains at least an acid cracking material, adding an acid peptizer, moulding, drying and roasting to prepare a hydrocracking catalyst carrier, wherein the acid cracking material contains modified molecular sieve and an amorphous acidic component; 2, preparing an Mo-Co active metallic salt solution, carrying out saturated impregnation on the carrier, drying, and roasting; 3, carrying out saturated impregnation on the roasted carrier by the use of a water-insoluble organic solvent, and drying; and 4, preparing an Mo-Ni or W-Ni active metallic salt solution, carrying out unsaturated impregnation on the dried carrier, drying, and roasting to obtain the hydrocracking catalyst. The hydrocracking catalyst prepared by the above method can carry out selective hydrogenation on a gasoline fraction and catalytic diesel oil in a cracked product, and the catalyst has high activity and high nitrogen tolerance. Therefore, long-term stable operation of a catalytic diesel oil hydro-conversion device under the condition of low hydrogen consumption is guaranteed.