Abstract: The paper analyzes the reason for the blockage of desuperheating water control valve of a boiler superheater in a power plant in Inner Mongolia. It is concluded that the product of flow accelerated corrosion of thermal system is deposited in the throttle hole of valve cage, resulting in the blockage of superheater desuperheating water control valve. The following measures are taken to solve the problem of frequent blockage of superheater desuperheating water control valve: adjust and optimize feedwater pH and deaerator exhaust valve, slow down the flow of steam system, accelerate the corrosion rate, reduce the iron content in steam system, and transform the valve cage structure of superheater desuperheating water control valve.