Facing the challenge of heavy oil processing, the chemical engineering details of flow characteristics, heat transfer in fluid catalytic cracking (FCC) riser reactor and the mechanism of cracking reaction, were particularly described, which were based on the fundamental research of turbulent gas-solid two-phase flow and lumped kinetics theories. In order to maximize the light oil yield and obtain clean gasoline, a new idea of "zoning-regulation" was proposed according to the parallel-sequential reaction mechanism and competing-adsorption between different hydrocarbons. Then the reaction performances of feedstocks with different properties were met by their optimal catalytic conditions. In view of the above works, a series of processing or new technologies matched by the novel structures or special equipments were successfully developed.