Abstract: Under the background of energy structure transformation, coal-fired power units are shifting from the main power source to the regulating support power source, and their flexibility improvement has become the key to ensuring the safe and stable operation of power systems with a high proportion of new energy. Aiming at the core problems of high minimum load, slow response speed and large peak-shaving cost faced by current coal-fired power units, this study systematically analyzes the key technology paths for flexibility improvement of the new generation: the boiler side realizes deep peak-shaving through wide-load combustion optimization and intelligent control; the steam turbine side adopts flow path modification and thermal-electrical decoupling technology to enhance variable-load capability; at the system level, molten-salt heat storage and AI algorithms are integrated to improve fast response characteristics. Engineering practice shows that the application of key technologies can significantly expand the peak-shaving range, reduce coal consumption, and create annual auxiliary service revenue of more than 30 million yuan for coal power enterprises. The research results have important engineering value and policy reference significance for promoting the clean and low-carbon transformation of coal power and building a new-type power system.