Abstract: The high temperature corrosion of water wall of coal-fired boiler is the key to the safety and stability of coal-fired generating units. Based on the brief introduction of the present situation and mechanism of the main corrosion types of the water-cooled wall of coal-fired boilers, the main corrosion prevention technologies commonly used in coal-fired boilers and garbage power generation boilers are summarized, and the characteristics of these technologies are summarized. Relatively speaking, the way of replacing the pipe wall material is restricted by many factors such as cost and boiler service life. Surfacing welding is widely used, but it is still challenged by the defects of high cost and low efficiency. Thermal spraying coating is the most commonly used method at present, but most of the thermal spraying coatings have low bonding strength, small pores and insufficient density. Among them, supersonic flame spraying is widely used, but the cost is high; In the high-temperature remelting technology, high-frequency induction remelting shows great development potential and broad application market.