The invention discloses a hydropower station group power generation optimization scheduling method with period coupling nesting. The method comprises the steps of according to historical radial flow data, solving a long-term optimization scheduling model for maximizing annular energy production amount, and obtaining early water levels and final water levels of n time periods after starting time ofthe hydropower station group; using the final water level of the first time period as the final water level boundary of a middle-period optimization scheduling model, when the middle-period optimization scheduling model satisfies water volume balancing restriction, performing middle-period optimization scheduling calculation, using the final water level of the middle-period optimization scheduling model as the early water level and the final water level of a next long-period scheduling model for performing boundary condition setting, and backspacing the starting time of the next long-term scheduling model by one time period; and if water amount balance restriction is not satisfied, introducing the current actual incoming water flow into water amount balance restriction for calculating a highest final water level at end of the first time period, and using the highest final water level as the final water level as the middle-period optimization scheduling model for performing boundary condition setting. The hydropower station group power generation optimization scheduling method can improve a combined optimization effect of stepwise hydropower stations.