Abstract: The establishment of a new power system is recognized as a pivotal strategic initiative to drive the transformation towards clean and low-carbon energy, ensuring the timely achievement of the 'Dual Carbon' goals. Against the backdrop of the new power system, renewable energy is gradually transitioning from a supplementary role to a primary power source, whereas coal-fired power generation units are assuming more flexible roles as 'guarantors of supply' and 'flexible regulators'. First, based on the practical engineering applications, this paper systematically analyzes the current state of flexible operation of coal-fired power generation units in the new power system. Targeting the three major types of host equipment, namely boiler, turbine and generator, the problems and reasons for the flexible operation of the unit in terms of operational safety and low load economy are sorted out in detail, and the existing solutions and deficiencies are analyzed. Then, new technologies for flexible unit operation are proposed at three levels, namely, ultra-low-load stabilized combustion burner, new boiler structure and full-load denitrification for boiler system, and at five levels, namely, new turbine structure, new blade, life monitoring system, new generator structure and dynamic phase adjustment for turbine power generation systems. Finally, the future research and development direction is prospected. This paper is expected to contribute to the clean and low-carbon, safe and efficient, flexible and intelligent transformation and development of China's coal-fired power generation.