<p>High-energy laser (HEL) systems have recently gained significant attention due to their precision targeting capability and rapid response in advanced defense applications. However, optical performance degradation caused by thermally induced deformation of reflective optics remains a critical challenge. This study presents an integrated thermo-structural-optical analysis framework using Ansys Zemax and Ansys Mechanical to predict optical performance under realistic operating conditions. Laser-induced absorption was evaluated and converted into thermal loads for transient structural analysis. The resulting deformation is then reintroduced into the optical model to quantify wavefront error (WFE) and system-level performance degradation. Parametric analyses were conducted considering mirror material, coating performance, laser power, and cooling conditions. In addition, the influence of structural stiffness and support conditions on deformation behavior was investigated. The results demonstrated that coating performance and thermal management dominate optical degradation, while structural stiffness significantly affected deformation magnitude. Material differences have relatively minor influence. The proposed approach enables accurate system-level performance prediction and provides a practical design methodology for high-power laser optical systems.</p>