The invention discloses a nuclear power water pumping energy-storage power station combined operation optimization method considering nuclear power unit maintenance. The nuclear power water pumping energy-storage power station combined operation optimization method considers comprehensive constraints of power grid start-up modes in different seasons (months), performs balancing monthly, provides peak load regulation capacity and water pumping energy-storage actual capacity of a power grid in each month, can be applied to water pumping energy storage to participate in power grid peak load regulation under the situation of large-scale grid connection of nuclear power units in further power grid, solves the difficulty that operation of nuclear power and water pumping energy storage of the power grid cannot be coordinated, can effectively increase the proportion of clean energy power generation in the power grid, helps to coordinate operation of various kinds of power supplies, and has broad application prospect.