Abstract: At a certain steel plant, the S6-high mill frequently encountered strip shape problems when producing wide ultra-thin strips. The strip shape acceptance rate was only 73.3%, leading to a significant drop in the product acceptance rate and severely restricting product quality and production efficiency. Analysis revealed that this issue is closely related to the setting of key parameters of the roll system. To address this problem, the whale optimization algorithm was adopted and optimized based on practical scenarios to search within a multi-dimensional parameter space. While considering equipment and process constraints, the optimal combination of key roll system parameters that minimizes strip shape deviation was identified. The resulting optimal roll system parameters were then applied to the actual production line for industrial verification. On-site verification results showed that the optimized parameters significantly improved the strip shape. Taking the shape target value of 5 IU as the criterion, the shape deviation along the entire length of the strip remained strictly stable within the target range after optimization. No defects exceeding the tolerance were detected during the production process, effectively solving the problem of low qualification rate of wide ultra-thin strips.