Abstract: Aiming to address issues such as severe machining deformation, high cutting temperatures, and excessive tool wear in aerospace stainless steel thin-walled components, this study investigates the efficacy of stress-free low-temperature clamping via a freezing process. A comparative experiment was conducted to assess the machining quality of stainless steel under both ambient and freezing milling conditions. The research systematically examines the effects of milling parameters and various freezing temperatures on workpiece characteristics, including milling temperature, flatness/parallelism, surface roughness, and residual stress. The results demonstrate that, compared to ambient milling, freezing conditions reduce the milling temperature by 53.29%～75.32%, respectively, and decreasing surface roughness by 3.34%～31.15%. Specifically, a freezing temperature of −10℃ yields the best improvement in parallelism, whereas −15 ℃ produces the optimal enhancements in both flatness and surface quality. The residual stress of the workpiece under freezing conditions is higher than that under normal temperature conditions. When the freezing temperature of the workpiece is −15 ℃, it is more significant to improve the residual compressive stress of the workpiece. These results provide important references for the low-temperature processing of aerospace stainless steel.