A catalytic conversion process can convert inferior feedstock to high quality fuel oil and propylene. A inferior feedstock is introduced into first and second reactor zone, wherein the feedstock carry out first step and second step reactions by contacting with catalytic conversion catalyst. Product vapors separate from spent catalyst by gas-solid separation. The spent catalyst is stripped, regenerated by burning off coke and then returns to reactor. The product vapors are introduced into separation system to obtain propylene, gasoline, diesel, fluid catalytic cracking gas oil (FGO) and other products. The FGO is introduced into hydrotreating unit and/or extraction unit to obtain hydrotreated FGO and/or extracted FGO. Said hyrotreated FGO and/or extracted FGO return 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 which are good chemical materials. The raffinate of said FGO is rich in chain alkane and cycloalkane which are suitable for catalytic cracking. More particularly, the invention relates to a process to utilize petroleum oil resources efficiently for decreasing the yield of dry gas and coke significantly.