To address the issues of a prolonged design cycle, high costs, and limited optimization effects associated with traditional giant tire side panels design that rely on empirical formulas and experimental validation, the side plate of a 33-inch large tire vulcanizing machine as the study object was used, and finite element analysis (FEA) methods and software such as ANSYS were employed. A three-dimensional model was constructed using UG, and a casting cavity design was used to replace the conventional solid structure. Various thicknesses and arrangements were configured, and meshing and material parameter settings, followed by mechanical and thermal analyses. The results indicate that when the distance between the casting cavity and the inner surface of the side plate is set to 80 mm, approximately 14.72% of material is saved. Additionally, the heating performance of six evenly distributed casting cavities is optimal, with 48.05% increase in heating speed compared to designs without casting cavities. This approach not only satisfies the structural performance requirements of the side plate but also reduces manufacturing costs, offering effective theoretical and practical guidance for the lightweight design of large tire side plates.