Distributed photovoltaic (PV) connecting into the distribution network will bring a significant impact on its operation. To ensure the loss reduction and energy saving effect of distributed PV grid-connected, this paper established an ideal distribution network model, and analyzed the impact of distributed PV grid-connected on the loss and voltage of distribution network. Based on the IEEE33 node system, simulation experiments are carried out on the MATLAB platform, and the results show that scientific selection of the capacity and location of PV connected to distribution network can reduce line loss and improve the voltage drop at each node at some extent.