ABSTRACT Due to the attractive advantages of magnetic gears resulting from contactless power transmission, these magnetic devices are replacing their mechanical counterparts. An axial flux magnetic gear with a gear ratio of 5.25 is investigated in this article. The high‐speed rotor is utilized with Halbach array permanent magnets (PMs). The entity of distance between high‐speed rotor (HSR) magnets reduces flux leakage and subsequently reduces torque ripple. To increase the maximum applicable torque and reduce the torque ripple on both sides, eight design parameters have been adopted and optimized using Taguchi method. The Taguchi method reveals each parameter's importance, rank, and influence on the proposed gear performance in terms of percentage by using the signal‐to‐noise ratios and analysis of variance, respectively. It is notable that this method decreases the required experiments, significantly. Low‐speed rotor (LSR) maximum applicable torque, LSR, and HSR torque ripples have been studied as single objective optimization problems. Furthermore, multiobjective function is studied as well and optimum levels of control factors are derived. In addition, the participation percentage of each control factor is obtained. The obtained results by 3D finite element method (FEM) indicate the performance improvement of the optimized structure. Finally, rotors' stresses have been studied to ensure structural stability and its effect on the overall performance.