Enhancing the flexibility of coal-fired power generation is a crucial for promoting clean energy consumption,green-orientedtransition of energy and energy security guarantee. The construction of a comprehensive standard system for the flexible coal-fired power generation is a key step for promoting flexible coal-fired power generation development. Based on the essence of flexible coal-fired power generation,the current reconstruction and construction of flexible coal-fired power generation face four main challenges were proposed,such as difficulties in breaking through on flexibility indicators,prominent safety issues under flexibility,a significant decline in economicindicators under flexibility,and difficulties in ensuring cleanliness under flexibility. In response to four key challenges,a preliminary framework for a comprehensive coal-fired power plant flexibility standard system has been established,taking into account goals,specialized categories,and functional sequences. This framework covers processes including general use, design, manufacturing, installation, testing, measurement, operation, and evaluation. Based on the current state of flexibility development in coal - fired power generation and relatedstandards,it is proposed to focus on several key areas for standard development: terminology and evaluation of flexibility standards,safe operation and life assessment of flexible units,efficiency evaluation under flexible operation of coal-fired units,carbon dioxide detection and pollutant emission control,and online monitoring of coal-fired power generation units. The efficiency evaluation methods will particularly addressnon-steady-state and deep load-following abnormal conditions,with special emphasis on online monitoring technologies for fuel qualityand coal flow,as well as the establishment of flexible control standards for fuel-burning-working fluid interactions. The proposed frameworkand suggestions can be served as revision and establishment references for the standards related to flexibility of coal-fired power generation.