Abstract: This article studies the influencing factors of the selection of the first and second reheat units for 2×1000 MW level high-efficiency ultra supercritical coal-fired power generation units. By using research methods, comparative methods, and theoretical analysis, the trend of the pre tax internal rate of return difference between the first and second reheat units of 1000 MW level high-efficiency ultra supercritical coal-fired power generation units is analyzed. Dynamic indicators are used to judge the economic advantages and disadvantages of the two, providing investors with preliminary analysis and judgment based on different scenarios during the initial investment stage.