Abstract: Since all kinds of coal-fired units in China have completed the transformation of ultra-low emission and large areas of denitration catalysts have entered the end of their life, the managers of power plants are faced with problems such as "when to reserve fresh catalysts" and "when and how to adjust the catalyst groups". To solve the above problems, relying on a unit of a coal-fired power plant affiliated to Zhejiang Energy Group Co., Ltd., the project used bypass flue gas to build a test platform for actual flue gas denitration catalyst performance, and used real flue gas to conduct catalyst activity detection, so that the activity detection result was closer to the real value of the working condition. On the basis of the activity and deactivation constants of monolayer and monolayer catalysts, respectively, the deactivation equation and terminal activity value were used to establish the calculation model for predicting the service life of the recombination catalyst group. Combined with the costs of catalyst renewal, regeneration, installation, storage and transportation, the economic evaluation of replacement adjustment was carried out, and the adjustment costs corresponding to the service life of the new catalyst combination unit formed by different adjustment schemes were obtained. Finally, a set of replacement and adjustment strategies for denitrification catalysts suitable for coal-fired power plants was developed after investigation and comprehensive consideration of the actual operation of the coal-fired power unit, the actual activity test results of single layer and monolithic catalyst platform, the estimated service life of the new catalyst group and the economic evaluation of replacement and adjustment. This strategy has been applied and implemented in a number of coal-fired power plants affiliated to Zheneng Group to guide the operation and management personnel of the power plant to carry out more efficient and economical precise control of denitrification catalysts, so as to realize a clear understanding of denitrification operation and evidential management of catalysts, which has a wide range of industry promotion and application value.