Abstract: Power supply capacity is one of the most important indexes to assess the modern distribution network. In this paper, according to distribution network with distributed generations, based on improved repeat power flow method, the analysis model of power supply capacity for distribution network with distributed generations is optimized, and the maximum power supply capacity is calculated. According to such characteristics as fluctuation and intermittence of distributed generations, the comprehensive assessment system of power supply capability for distribution network with distributed generations is built, and power supply capability in different period of time can be comprehensively evaluated based on the improved AHP. A case is also given to testify the validity and feasibility of proposed method, which can assess power supply capacity of distribution network with distributed generations clearly and objectively.