Abstract: In order to accurately evaluate the carrying capacity of power grid to distributed photovoltaic power station,based on the analysis of six influencing factors,including the power grid operation characteristics,power supply installation composition,shortcircuit current,power quality,voltage deviation and loss, relay protection. the calculation and evaluation method of distributed photovoltaic carrying capacity was put forward considering the characteristics of large-scale urban power grid. And then an example of the large-scale urban power grid. And then taking the large-scale urban power gird as an example,the feasibility and practicability are verified. The example results show that this method can accurately evaluate the new distributed photovoltaic carrying capacity of 10 kV to 220 k V bus of power grid,and also provide the guidance for the planning,construction and operation analysis of distributed photovoltaic access to large urban power grid.