The invention relates to a 10kV distribution circuit distributed photovoltaic constant volume method and system. The method comprises: characteristic parameters of an object circuit is acquired; characteristic parameters of a corresponding ground state circuit are selected according to the type of the object circuit, the characteristic parameters of the object circuit are performed a per-unit process, and per-unit parameters are obtained; an end photovoltaic limiting capacity elimination proportion is acquired according to the per-unit parameters and a circuit end photovoltaic limiting capacity elimination proportion constant volume formula corresponding to the type of the object circuit; the end photovoltaic limiting capacity elimination proportion is corrected according to the distributed photovoltaic practical accessing position information of the object circuit and the type of the object circuit, so that a eliminable photovoltaic limiting capacity proportion of the is obtained; and the eliminable photovoltaic limiting capacity is obtained according to the distribution transformer total capacity of the object circuit and the eliminable photovoltaic limiting capacity proportion. The invention has guiding significance for a constant volume problem of distributed photovoltaic accessing power distribution network.