<p>Optimization of stacking sequences is a crucial approach for reducing the weight of laminated composite structures while enhancing their mechanical performance. In previous studies, stacking sequence optimization was typically conducted using the stacking sequence table (SST) representation, which treats different regions of a laminate structure as an integral whole. As a result, regions with the same thickness are enforced to share identical stacking sequences, leading to poor optimization performance for laminates with multi-peak thickness distributions. To overcome this limitation, the multi-sequence stacking table (MSST) approach was introduced, which allows different regions to be treated separately. However, in MSST, the peak thickness is fixed at the design stage and cannot be further explored. To address this issue, the multi-peak stacking sequence table (MPSST) approach was developed, enabling direct optimization of different thickness peaks. In this study, the MPSST approach is innovatively applied to the CRM wingbox skin structure, going beyond the limitations of the conventional eighteen-panel theoretical model and addressing the gap in exploring thickness distributions of laminate structures in skin optimization. The wingbox skins are divided into 40 design regions and further grouped into 3 region groups in accordance with the region group division strategy, with the objective of weight reduction. Results show that, compared with the SST approach, the wing skin mass is reduced by 711 lb, corresponding to a weight reduction of 4.03%.</p>