A catalytic conversion process to convert inferior feedstock to high quality fuel oil and propylene is disclosed. Inferior feedstock is introduced into first and second reactor zone, wherein first step and second step reactions occur by contacting with catalytic conversion catalyst. Product vapors include fluid catalytic cracking gas oil (FGO) which is introduced into a hydrotreating unit and/or extraction unit to obtain hydrotreated FGO and/or extracted FGO. Hydrotreated FGO and/or extracted FGO returns to the first reactor zone and/or another catalytic cracking unit to obtain propylene and gasoline. The extracted oil of said FGO is rich in double ring aromatics and the raffinate of said FGO is rich in chain alkane and cycloalkane. More particularly, the invention utilizes petroleum oil resources efficiently for decreasing the yield of dry gas and coke significantly.