Abstract: As the core heated surface of a coal-fired boiler furnace, the water-cooled wall"s safe and stable operation directly determines the unit"s availability and economic efficiency. Addressing the frequent leakage issues in operational coal-fired units, this study identifies material defects, thermal stress fatigue, high-temperature corrosion, and fly ash wear as the four primary causes of water-cooled wall leakage through on-site inspection, fault tracing, and mechanism analysis of our plant"s boiler steam-water system. Combining operational conditions, a comprehensive prevention and control technical system—"material upgrade, structural optimization, operational management, and detection early warning"—is proposed. Practical verification demonstrates that this system significantly reduces water-cooled wall leakage failure rates, providing both theoretical foundations and practical references for the safe operation and maintenance of similar units.