Abstract: In order to analyze the low-carbon contribution of PV generation to the power system,this paper proposes an analysis method of the influence of PV injection power uncertainty on carbon emission flow of the power system.Firstly,through the output of photovoltaic units and a power model of system nodes,the functional expression of illumination intensity and the total carbon flow rate of the system nodes is established.Secondly,the directed path algorithm is used to calculate the path output distribution factor matrix,and the randomness of the PV output is transferred to a balance unit.Based on the correlation matrix of the carbon flow rate between the unit and the system node branches,the influence factors of the PV injection power on the nodes and branches are calculated,and the uncertain characteristics of the carbon emission flow in the power system under the PV injection power are obtained.Finally,the correctness of the proposed method is verified by the measured illumination intensity and the analysis results of IEEE14-node examples.The node carbon potential,branch carbon flow rate and influence factors of the centralized and distributed access power system of the photovoltaic electric field are calculated,and then the low-carbon contribution of photovoltaic access to the power system is quantitatively analyzed.