<p>Thin-walled blades made of Ti-6Al-4V titanium alloy are critical core components widely used in aerospace engineering due to their high specific strength. However, their low structural stiffness and complex curved geometries frequently cause severe chatter and machining deformation, which directly deteriorate final machining quality and process efficiency. To address these challenges, this study systematically investigates auxiliary support strategies for compliant grinding of thin-walled blades. By rationally designing and arranging customized auxiliary support structures, the overall stiffness of the machining system is effectively improved, and deformation-induced errors are significantly suppressed. Three different auxiliary support configurations—Three-Point Central Support (TPCS), Four-Point Rectangular Support (FPRS), and Four-Point Diamond Support (FPDS)—were designed and quantitatively evaluated using Abaqus-based finite element simulations combined with systematic grinding experiments. The experimental results validated the simulation model, with relative errors of 8.16% for normal contact force and 5.9% for grinding mark size and depth, confirming high predictive reliability under different conditions. Simulation results indicate that all three auxiliary support strategies significantly improve grinding quality. Among them, the TPCS scheme achieves optimal comprehensive performance, with notable advantages in contact force uniformity, machining deformation suppression, and grinding consistency. This study establishes a solid theoretical foundation and provides key technical guidance for high-precision, anti-deformation compliant grinding of thin-walled blades.</p>