The diagnostic and therapeutic paradigm for lower extremity arteriosclerosis obliterans (ASO) is undergoing a fundamental shift from conventional morphology-based assessment toward functional evaluation and predictive medicine. Numerical simulation techniques that integrate computational fluid dynamics (CFD) and finite element analysis (FEA), grounded in patient-specific imaging data, have emerged as a central driving force of this transformation. This review systematically elucidates how these approaches enable the construction of vascular “digital twins” to achieve precise quantification of the hemodynamic environment associated with ASO lesions, virtual monitoring of disease progression, and preoperative optimization of therapeutic strategies. Particular emphasis is placed on the critical role of numerical simulation in supporting clinical decision-making, such as evaluating the necessity of interventional treatment and predicting the mechanical responses of endovascular devices. Furthermore, the potential, current challenges, and future directions of numerical simulation in advancing personalized and precision management of ASO are comprehensively discussed.