Abstract: It is complicated to evaluate the power supply capability of distribution network with connected distributed generators（DGs）.This paper mainly studies the influence of grid-connected DGs on the power supply capacity of the distribution network.The blind-number models of uncertainty factors in the power grid is developed though the judgement matrix method.A power supply capability evaluation index based on the blind-number theory is proposed.By combing with the repeated power flow method,the index is used to evaluate the power supply capability of the distribution network with DGs.Finally,the feasibility and necessity of the proposed method is verified by an example.