Method for catalyzing lightening of diesel oil and obtained product

The invention discloses a method for converting catalytic diesel oil to light fraction and an obtained product, and the method for converting catalytic diesel oil to light fraction comprises the following steps: step 1, carrying out hydro-upgrading treatment on catalytic diesel oil to obtain hydrogenated diesel oil rich in naphthenic aromatic hydrocarbon; 2, carrying out a catalytic cracking reaction in a riser reactor, introducing C4 olefin into the bottom of a riser, and carrying out a contact reaction with a catalytic cracking catalyst; light gasoline is introduced into the lower part of the riser and is subjected to a contact reaction with a catalytic cracking catalyst; according to the method, the C4 olefin cracking propylene production process, the light gasoline modification process and the catalytic diesel oil hydrogenation modification-catalytic cracking combination process are effectively combined, co-catalytic cracking of the three raw materials is achieved, and the catalytic cracking efficiency is