Abstract: The application of heavy oil catalytic cracking 11 lumping kinetic model to commercial unit is discussed in this article,including the simulation calculation of the upper mixing ratio of vacuum residual oil and coking wax oil as well as the combination technique of catalytic cracking and aromatic extraction.The upper mixing ratio simulation provides a way to make the best use of these low grade materials and points out a direction to increase the throughtout capacity of catalytic cracking units.The simulation of the combination technique provides the judgement basis for running the aromatic extraction unit or not.The results of the simulation calculations show that the heavy oil catalytic cracking kinetic model is credible and has good extrapolation ability,and the software for the kinetic model can be used not only for the cases cited but also for other optimization simualtion calculation of FCC units such as choosing the best operation conditions and comparing the different process schemes.