Deep catalytic cracking process (DCC process). Developed by China Research Institute of Petrochemical Technology, this process uses heavy oil as raw material and solid acid shape-selective molecular sieve catalyst for cracking reaction under mild reaction conditions to produce low-carbon olefins or isomeric olefins and high-octane gasoline. The process has been industrialized by using fluidized catalytic cracking technology for reference and adopting fluidization, continuous reaction and catalyst regeneration technology.