The flange of the turbine rotor, as a critical load-bearing joint of the aircraft engine, is prone to strength failure, which directly affects the safety and reliability of the engine. This paper aims at the issue of excessive stress which may lead to failure at the bottom region of the flange of an aircraft engine turbine disc, and proposes a highly efficient shape design optimization method for the flange of rotor. Select 8 points distributed circumferentially along the flange’s outer contour as shape control nodes, and construct a parametric model driven by circumferential shape parameters, using cubic B-spline curves and enabling the deformable design of the flange shape. Based on a collaborative optimization framework of parametric geometric modeling and finite element analysis and combined with the efficient Pointer optimization strategy, establish an optimization process for the turbine disc flange, with the objective of reducing the maximum stress in critical areas. The optimization results show that the maximum stress reduction in key areas reaches 26.70%, which is better than the 5.15% reduction achieved through traditional dimensional optimization, confirming the superiority of the proposed method. Optimization of the stage 1–2 and stage 2–3 flanges resulted in maximum stress reductions of 19.96% and 23.80% respectively, demonstrating the universality of the method and providing important support for the design and improvement of engine models.