Complex surface optical components have been widely used in the forefront of aerospace, space exploration, military reconnaissance and modern information technology due to their advantages in improving aberrations, improving imaging quality, reducing system unit quantity and weight, reducing power loss, improving accuracy and stability. As one of the main methods to process high precision optical component, Computer controlled optical surfacing (CCOS) has also been applied in the processing of complex surfaces. However, due to the incompletely contact between the polishing pad and the surface of the workpiece especially the high-steepness and large curvature area during processing, the phenomenon of unstable removal function is generated, which leads to deterioration of surface accuracy and even flaws..In this paper, the elastic fiber modeling theory derivation, ABAQUS finite element simulation and experimental verification method are used to study the contact problem between the polishing disc and the workpiece surface and the stress distribution when processing complex curved surfaces, and the deformation layer of the polishing pad is optimized. An improved semiflexible polishing disc was used to machine a complex curved aluminum alloy mirror, which improved the surface quality while controlling the change in surface accuracy (PV value) within 10%, verifying the improved polishing disc processing. The effectiveness of complex surfaces.