This study examines the integration of advanced composite materials into metro infrastructure systems with particular emphasis on corrosion-resistant reinforcement technologies, composite-based protective linings, and innovative strengthening solutions. International implementation practices, engineering performance indicators, economic implications, and long-term sustainability aspects are systematically evaluated. The findings reveal that fiber-reinforced polymer (FRP) systems significantly enhance structural durability, extend operational lifespan, and reduce lifecycle maintenance costs when compared to conventional steel-based solutions. The research further identifies technological challenges and outlines strategic directions for future development in underground transportation infrastructure..