Abstract: The grass-root large-scale refinery with a capacity of 12.0 Mt/a processing Saudi Arab medium crude is studied for maximizing clean gasoline production by PIMS linear programming mode. Two typical refining configurations of Case 1 (the combination of ARDS+RFCC) and Case 2(the combination of RDS+RFCC and VGO HCR) are compared. The results show that the Case 1 with 4.4744 Mt/a gasoline production is better than the Case 2 with 4.0516Mt/a gasoline. Based on Case 1 selected, more gasoline with the production of 0.718 Mt/a can be further increased by FCC light fraction etherification, LPG alkylation and ethylbenzene synthesis of benzene and thin ethylene in RFCC. And clean gasoline product meeting the GB17930—2013 standard can be obtained by optimization of blending ratio of the gasoline pool components.