The development of advanced nuclear energy systems imposes stringent requirements on the service stability of nuclear materials under extreme environments characterized by multiple stressors. Continuous silicon-carbide-fiber-reinforced silicon carbide (SiC_f/SiC) ceramic matrix composites possess advantages such as low density, excellent high-temperature mechanical properties, corrosion resistance, and irradiation tolerance. Furthermore, SiC_f/SiC composites demonstrate a pseudo-ductile fracture behavior under external forces, positioning them as highly promising structural materials for advanced nuclear energy systems. This study systematically summarizes the fundamental research framework on nuclear-grade SiC_f/SiC composites at the material, component, and service performance levels. It also analyzes the developmental trends in this field among traditional nuclear powerhouses such as the United States, France, and Japan, as well as in other emerging nuclear energy countries and China. Furthermore, the study identifies existing issues and challenges faced by China’s nuclear-grade SiC_f/SiC sector in terms of raw materials, data accumulation, and patent standards, and proposes targeted measures and suggestions: (1) strengthening the research and development of material preparation technologies, (2) developing a new paradigm of research and development, (3) reinforcing the industry-university-research-application cooperation, and (4) enhancing international exchanges on the basis of maintaining independence. The aim of the study is to provide guidance and reference for the research directions and policy-making in China’s nuclear-grade SiC_f/SiC sector.