Distributed photovoltaic access to the distribution grid leads to changes in the magnitude and direction of the transmitted power. The voltage distribution is affected in steady state. This paper proposed a calculation method for the impact of distributed PV on voltage network losses. The impact of high penetration PV on voltage network loss is analyzed. A simulation model was established in MATLAB. The influence law of different PV access locations and capacities on was investigated voltage and network loss under whether or not to consider PV output and load characteristics. The results showed that, regardless of whether the PV output and load characteristics are considered, PV has a certain lifting effect on the grid voltage. And it reduced the line power flow and thus reduces the network loss. The closer the PV location is to the end of the line, the better the voltage improvement effect is. The more obvious the reduction effect on the line network loss is. Among them, without considering the PV power and load characteristics, PV multi-point access should be uniformly distributed in the line, can effectively cover the load in the line and support the line voltage. The research in this paper helps to guide the relevant research and practical application, to achieve the purpose of reducing the adverse effects of distributed photovoltaic.