The present invention provides a hydrocracking catalyst containing amorphous silica-alumina and preparing method. The amorphous silica-alumina in the catalyst employs parallel current coexisting method, not only has a simple process, easily controlling, but also employs CO2 and wind mixing, the reactant is adequately mixed, silica and alumina are effectively mutual action, a large specific surface area and a large specific pore volume are formed, pore distribution is very concentrative, 4-10nm pore volume is about 85%-95% of the total pore volume, pore volume which aperture is bigger than 15nm, is below 5% of the total pore volume. The amorphous silica-alumina provides enough channel to the reactant, benefits for enter and exit of reactant and resultant, greatly enhances effectively element of carrier, enhances the homogeneity of the acid center distributing on the channel, in addition, the invention provides larger space and specific surface to carry metal, the hydrogenation metal has high dispersivity, the catalyst not only has feasible schizolysis activity, but also bas high hydrogenation activity and medium oil selectivity.