<p>This paper conducts a systematic study addressing the challenges of clamping deformation and cutting deformation control in the turning process of ultra-high-strength steel thin-walled gear rings used in heavy-duty vehicle retarders. A magnetic coupling simulation model is developed for analyzing the stress characteristics and deformation mechanisms of thin-walled gear rings under the constraints of permanent magnetic fixtures. This allows to reveal the conical phenomenon during the turning process and the circumferential periodic stress phenomenon of thin-walled gear rings. In addition, the obtained results show that the magnetic field can alter the plastic deformation behavior and thermal conductivity of ultra-high-strength steel workpieces, which significantly reduces the cutting heat and friction during machining, allowing to perform control over the cylindricity of the outer circle of thin-walled gear rings during cutting. The results of this study provide a theoretical basis and practical guidance for the quality control of thin-walled gear ring turning under the constraints of permanent magnetic chucks. Moreover, they have significant application value for increasing the accuracy of the machining of key components in heavy-duty vehicles.</p>