Loop flow technology has been widely studied and used in the fields of bioengineering，wastewater treatment，organic chemical，direct coal liquefaction，etc.，but existing research mostly focuses on gas-liquid，liquid-solid and gas-liquid-solid system.In the recent years，not only the research of loop flow technology has developed to gas-solid system，but also the application has entered to the field of petroleum processing.This paper mainly summarizes the processes in research and industry application of gas-solid loop flow technology in rough cyclone separation，stripper，heat exchanger，olefin reduction reactor，combustor for petroleum coke and so on of FCCU.Furthermore，the studies and applications of gas-liquid loop flow technology in heavy oil suspending bed hydrogenation and gas-liquid-solid loop flow technology in separating hydrogen from refinery gas by hydration are reviewed.