Abstract: Under the national "dual carbon" energy strategy, new energy sources such as wind power and photovoltaic will gradually become the main power source of the power grid, and coal-fired units will take up more auxiliary services such as peaking and frequency regulation to solve the impact of intermittent and random new energy sources on the power grid. In this paper, we study the use of hydrogen energy storage to improve the auxiliary service capacity of coal-fired units, and the remaining power in the peaking process will be used to make hydrogen by electrolysis of water to produce high-purity hydrogen for sale to hydrogen fuel cells or other chemical industries. Under the current auxiliary service policy, coal-fired units can obtain more peaking subsidies and improve the economics of coal-fired units while ensuring the completion of auxiliary services such as peaking and frequency adjustment.