The design of the pinion shaft plays a critical role in the efficiency and durability of pelletizer gearboxes used in industrial applications. This study focuses on the optimization of the pinion shaft design utilizing advanced numerical software, ANSYS. The aim is to enhance the performance and reliability of the pelletizer gearbox by employing computational analysis techniques to refine the pinion shaft geometry. The optimization process involves the utilization of ANSYS software to simulate various loading conditions and operational scenarios. Finite Element Analysis (FEA) is employed to assess the structural integrity of the pinion shaft under different mechanical stresses, including torsion, bending, and fatigue. Through iterative iterations, the design parameters such as material selection, dimensions, and geometrical features are systematically adjusted to achieve optimal performance while ensuring mechanical robustness and longevity. Furthermore, the study considers the influence of factors such as material properties, manufacturing processes, and operating conditions on the pinion shaft's performance.