The deep processing technology for high-purity raw materials of critical metals serves as a vital technical link that connects mineral resources and high-end manufacturing industries, bearing great significance for safeguarding the security of national strategic resources. This study reviews the progress of high-purity processing technologies for typical critical metals including gallium, indium, germanium, titanium, tungsten, molybdenum, vanadium, tantalum, niobium and scandium, and conducts a comparative analysis of their industrial application status, technical maturity, international benchmark levels, and existing technical shortcomings. The results indicate that China has established a complete industrial system and large-scale production capacities for conventional critical metal products with a purity of 4N‒5N grade. However, there remain prominent gaps between China and international advanced levels in terms of preparation stability of ultra-high-purity products above 6N grade, precision removal of trace impurities, and independent research and development of high-end core equipment. Based on a technical maturity evaluation, it is projected that future deep processing technologies for high-purity raw materials of critical metals will exhibit four major development trends: an extreme elevation in product purity, diversified and complex development of material components, nanocrystallization and compounding of powder materials, and an evolution of separation mechanisms toward multi-field coupling. Oriented toward 2040, a medium- and long-term development roadmap for the industry is proposed, focusing on five key development directions: ultra-high-purity preparation, complex system separation, nano and composite powder preparation, multi-field-coupled targeted separation, and intelligent green metallurgy. Corresponding countermeasures and suggestions are proposed from five dimensions: consolidating industrial foundation, optimizing resource allocation, strengthening basic research, overcoming equipment technical bottlenecks, and advancing artificial intelligence empowerment. This study can provide scientific support for the independent development and strategic planning of China's critical metal industrial chain.