The invention relates to an active power output dispatching method of a centralized energy storage power station. The method comprises: using a minimum power distribution network active power difference fluctuation as an objective function, performing optimized dispatching on an energy storage power station combining with real-time dispatching, quasi real-time dispatching, and rolling dispatching; according to the optimized dispatching, establishing a centralized energy storage power station active power output dispatching mathematics model; determining constraint conditions of the centralized energy storage power station active power output dispatching mathematics model; performing softening process on soft constraint conditions in the constraint conditions, and obtaining a final optimized dispatching model on the centralized energy storage power station active power output dispatching mathematics model; and according to the final optimized dispatching model, solving and outputting energy storage power station active power dispatching instructions of a present dispatching period. The technical scheme can ensure the schedulability of the energy storage power station in the whole dispatching period, and effectively make up active power difference of photovoltaic output and load requirements, so as to solve a problem of active power difference fluctuation of a power distribution network in the dispatching period.