The invention discloses a method for preparing a hydrocracking catalyst. According to the catalyst, firstly, a mixed solution A containing Ni and W and a sodium metaaluminate alkaline solution are subjected to a gelatinization reaction in a parallel flow manner, obtained slurry is aged, then, a mixed solution B containing W, Si and Al components and ammonia water are added to the aged slurry in aparallel flow manner to be subjected to a gelatinization reaction, aging is performed after a suspension of a molecular sieve is added, then, drying, forming and re-drying are performed, treatment isperformed with a mixed aqueous solution of aluminum salt and organic acid, washing, drying and calcination are performed, and the hydrocracking catalyst is prepared. The hydrocracking catalyst is applied to medium oil type hydrocracking catalysts and has good activity and selectivity.