High-temperature mechanical strength is a key performance determinant for the long term, stable operation of advanced energy systems and components in high-temperature service and has been a disciplinary branch in the mechanical strength theory. Its research and development have accompanied major industrial technological advances. The research paradigm has shifted from early empirical formulas and single damage model to a structural integrity assessment framework characterized by mechanistic interpretability, prediction orientation, and evidential reproducibility. Building on the historical trajectory of the field together with bibliometric analysis and keyword clustering, the phase specific migration of research hotspots and the evolving knowledge structure were delineated. Recent progress was synthesized along three complementary themes, namely multiscale modeling, multiple damage coupling, and multidisciplinary integration. The synthesis covered material deformation and damage mechanism, damage evaluation and life assessment, and in-service monitoring and reliability assessment, thereby establishing a traceable mapping from microstructural mechanisms to engineering applications. Looking ahead, advances are expected to deepen in multiphysics coupling, intelligent decision-making algorithms, and standards system development. Critical challenges include bridging high-fidelity models and real-time prediction, establishing robust mappings from microstructure to service life, and translating theoretical modeling into engineering codes.