To address the deformation issues in milling large-scale thin-walled structures, this study proposed a novel machining deformation simulation strategy by integrating process characteristics with the nonlinear solver framework of the structural analysis software SABRE. A finite element simulation workflow was established, incorporating initial residual stress fields and progressive element failure mechanisms and developing specialized milling deformation simulation software. Furthermore, process parameters, including milling forces and Tool-paths information, were systematically incorporated into the finite element model. Numerical simulations of typical frame-type structural components were successfully implemented, demonstrating deformation patterns consistent with experimental measurements and commercial software predictions. The validation results confirmed that the proposed simulation strategy and workflow can accurately predict machining-induced deformations in aircraft structures.