The invention belongs to the field of optimal dispatching in electric systems and discloses a coordinating optimal dispatching method for large water electricity, small water electricity and wind electricity. The method is characterized in that absorbing the largest electric quantity serves as the purpose, the confidence degree of an objective function and the partition output out-of-limit chance constraint are comprehensively taken into account, and then a coordinating optimal dispatching model for largest short-term output electric quantity of the large water electricity, the small water electricity and the wind electricity based on a chance constraint planning is constructed; power generation predict error distributions of the wind electricity and the small water electricity are obtained by the adoption of a nonparametric kernel density estimation method; output fluctuations of the wind electricity and the small water electricity are balanced by utilizing good adjustment capacity of the large and middle water electricity, and solving is performed by the adoption of an improved particle swarm optimization method and combined with Monte Carlo simulation. The method can fully take uncertainty of the small water electricity and uncertainty of the wind electricity into account, effectively coordinate large water electricity energy, small water electricity energy and wind electricity energy, adjust the remaining to supplement the lack, preferentially absorb the small water electricity and the wind electricity, provide a balancing basis of operation risks and expected absorbed electricity quantity for a dispatcher, and provide a reference for input of other types of large-scale intermittent energy.