Abstract: During the operation of a heavy plate rolling mill, the relevant parts dimensions of the roll system change due to equipment wear, assembly accuracy, and roll system adjustments. These changes affect the height of the rolling line and the normal operation of the roll system. This paper analyzes the influence of the roll system structure and its related dimensions on the rolling line, and accordingly adjusts the rolling line to meet the requirements of the rolling process. Meanwhile, in the control process of the existing roll gap set value, the transmission process of the set value calculated by the Level 2 system is optimized. The Level 2 pass schedule is received in advance and the roll gap is pre-calculated. The roll gap distribution between the upper and lower roll systems is also optimized, and the waiting and positioning time of the rolling mill is reduced. Through the research on the structure of the mill roll system and the optimization of roll gap timing control, the adverse effects of the rolling line on roll gap positioning and rolling process are avoided, and the rolling control level and rolling rhythm are further improved.