Abstract: The traditional method of measuring hydrogen conductivity of water samples has a series of disadvantages,such as the unstable online monitoring data,the failure of the cation resin,the low regeneration degree,the harm of regenerated drugs and the tedious routine maintenance. The new CACE method for measuring hydrogen conductivity can realize continuous and synchronous online monitoring of multiple indicators,without failure and regeneration problems,and basically zero maintenance in operation. A heat boiler of combined-cycle unit requires high p H feedwater operation. Large amount of ammonia addition leads to frequent failure of hydrogen exchange column,and poor monitoring of water vapor hydrogen conductivity rate. As the research object,the combination of the actinic resin method and CACE. Continuous tracking and detection of water samples by ion chromatography and atomic absorption,CACE technology has obvious advantages. The reliability and stability of water vapor monitoring data is improved,which provides some reference for power plant to solve such problems.