Abstract: Inconel718 alloy strip serves as a critical material for manufacturing fuel assembly grid springs in pressurized water reactors. However, the strip frequently encounters shape defects during 20-high mill rolling processes due to the material's high work-hardening rate and deformation resistance. To investigate the influence of key rolling parameters on the strip shape and develop optimization strategies, this study established a rolling simulation model integrating a 20-high mill roll system with Inconel718 alloy strips using ABAQUS finite element software. The effects of friction factor, rolling tension, and axial shifting amount of the first intermediate roll were analyzed, and the ranges of critical rolling parameters were determined. The results show that as the friction factor or rolling tension increases, the variance of transverse thickness displacement decreases, the residual stress distribution becomes more uniform, while edge drop and crown remain nearly unchanged. When the friction factor is controlled at 0.14, the variance of transverse thickness distribution is reduced to 0.000 9. With a rolling tension of 200 kN, the variance decreases to 0.001 1. Increasing the axial shifting amount of the first intermediate roll effectively reduces edge drop and crown. At a shifting value of 65 mm, edge drop and crown decrease to about 3.68 μm and 14.37 μm, respectively. The recommended parameter ranges for improving flatness are as follows:friction factor of 0.14, rolling tension of 180-200 kN, and axial shifting amount of 40-65 mm.