The invention provides a chance constraint planning based optimal configuration method of a distributed energy source. The method comprises the following steps of building a comprehensive optimal configuration model of the distributed energy source; determining a chance constraint condition of the comprehensive optimal configuration model of the disturbed energy source; determining an energy storage system configuration principle of the comprehensive optimal configuration module of the distributed energy source; and figuring out the comprehensive optimal configuration model of the distributed energy source. With the method proposed by the invention, the acceptable capability of a power distribution net on the distrusted energy source is effectively improved, the energy efficiency target and the low carbon target of a planning scheme can be met, economic requirement also can be met, the problems of site selection and constant volume of the distributed energy sources in places with different resource levels and economic development degrees can be solved, the application of the distributed energy source at a large scale is ensured, and the environmental pollution and energy crisis caused by fossil energy can be effectively relieved.