Abstract: By sorting out and researching the policies for flexibility transformation of coal-fired power units in recent years and the current situation of flexibility at home and abroad, it is found that under the“dual carbon” goal, the pace of my country’s energy transformation has accelerated. In response to the call of national and local policies, the power system actively improve the peak shaving capacity of coal-fired power units, and improve new energy absorption capacity. Aiming at the problems faced by increasing the peak shaving capacity of coal-fired power units, a comprehensive technical route for transformation involving systems such as heating, boilers, steam turbines, environmental protection facilities, and thermal control is proposed. In addition, although thermal power has to sacrifice certain efficiency and economy when providing a large number of auxiliary services, it can also obtain compensation benefits brought by the system due to the contribution of auxiliary services. Without considering the impact of the power grid system on the demand for peak-to-valley regulation capacity due to changes in user-side demand, it can be predicted that the demand for the total capacity of coalfired power flexibility retrofit units will increase significantly in the next few years. However, the flexible development of thermal power is still constrained by technology, funds, compensation policies and other aspects.