The invention relates to a method for calculating the admitting capability of a distributed power supply based on a hierarchical and divisional idea. The method comprises the following steps: 1) determining a regional power grid to be evaluated and a voltage class; 2) drafting a distributed power supply access planning scheme; 3) acquiring the access capacity, the model, and the parameters of the distributed power supply in the distributed power supply access planning scheme; 4) dividing the regional power grid into various ranges so as to obtain hierarchical and divisional regional power grid ranges; 5) evaluating the adaptability of the power grids in respective ranges to obtain respective evaluation index values and index scores; 6) subjecting the regional power grid to distributed power supply adaptability evaluation to obtain a regional power grid adaptability score; and 7) determining whether the regional power grid has a capability to admit the distributed power supply and obtain the maximum admitting ability of the regional power grid to the distributed power supply by means of loop iteration. The method can provide theoretical and technical support for distributed power supply grid-connected scheme evaluation and selection, and regional distributed power supply and power grid coordination planning.