Abstract: The Crude benzene hydro-refining unit is to remove unsaturated hydrocarbons and a small amount of sulfide by hydrogenation，and further rectify and refine the compositions to produce higher value-added products such as benzene，toluene and xylene．The basic loops of the unit are all controlled by PID，and the coupling correlation between material and energy in the unit makes the PID control of some basic loops less effective．For this reason，advanced control and optimized technology were applied for the crude benzene hydro-refining process，which significantly improved the quality of the controlled variables in the unit，reduced the labor intensity of the operators，improved the energy consumption of the unit and achieved good economic benefits．

Key words: Crude benzene hydro-refining, Optimization of basic control loop, Multi-variable control, Optimization