With the continuous promotion of the national carbon peaking and carbon neutral policies, as well as the strategic plan of the energy revolution, new energy represented by distributed generation (DG) has been widely used in the power industry with its advantages of renewable and environmental protection, but it has caused serious changes in the topology structure of power distribution network, exerted a serious influence on power flow distribution, network loss and harmonics, as well as endangered the safe and stable operation of the power distribution system. In this paper, through theoretical derivation on the power flow characteristics of DG, establishing the IEEE33 node model, and using Matlab/Simulink platform and digital simulation of the distribution network model, the author validates the impact of different DGs on power flow distribution, providing effective theoretical and simulation support for the safe operation of the distribution networks of DG.