In this study, a large-scale magnetic rotator for hydrogen production boosting was designed. The study addresses the challenge of selecting and designing mechanical components for a dynamic magnetic field (DMF) magnetic rotator in a green hydrogen electrolysis power plant, focusing on ensuring component reliability and efficiency under operational stresses. The aim is to determine suitable machine element materials (shaft, clutch, gears, etc.), allowable shear stress, and interconnection mechanisms through theoretical and practical evaluations. The method includes calculating the allowable shear stress for the spline based on carbon steel tensile strength, applying safety factors for material properties and load considerations, and determining shaft diameter using torque and shock load factors. Standard catalogs guide the selection of interconnections like clutches, gears, and bearings to ensure compatibility and performance. The results indicate that a 95 mm diameter S30C carbon steel shaft, with an allowable shear stress of 7.8 kg/mm2, meets the design requirements. The chosen spline dimensions and a 12.5 MW, 14-pole induction motor align with the system’s needs, ensuring reliable operation. The discussion highlights the critical balance between theoretical predictions and practical application in design optimization. It underscores the importance of incorporating safety factors and verifying component suitability to ensure robust performance of the magnetic rotator. This study provides a comprehensive approach to design optimization, integrating theoretical analysis with practical considerations to achieve optimal performance and reliability. The design output of this study can be used to boost the hydrogen evolution reaction in the SIEMENS Sylizer 300 electrolysis cell.