The invention discloses a hydro-conversion process for catalytic diesel oil. The hydro-conversion process comprises the following steps: (1) firstly putting a mixture of catalytic diesel oil and hydrogen into a hydrogenation reactor to have a hydrofining reaction; (2) enabling a hydrofining reaction effluent to directly enter a cracking reactor to contact and react with a hydrocracking catalyst bed in the cracking reactor; wherein upper and lower hydrocracking catalyst beds are graded and loaded in a hydrocracking reactor, a catalyst of the upper bed takes W-Ni and/or Mo-Ni as the active metalcomponent, a catalyst of the lower bed takes Mo-Co as the active metal component, and a modified Y molecular sieve and carbonized alumina are taken as carriers; (3) separating and distilling the hydrofining reaction effluent obtained in the step (2) to obtain a naphtha component and a diesel component, wherein the naphtha component is directly discharged out of a device to serve as high-octane gasoline blending component, the diesel component is directly discharged out of the device to serve as a blending diesel, and the naphtha component and the diesel component can also be recycled back inthe cracking reactor for further reaction. The process reduces the hydrogenation saturation of the generated gasoline component and increases the octane number of the gasoline component on the premiseof better meeting the conversion rate of the catalytic diesel oil.