Abstract: For the stochastic characteristics of the power output of photovoltaic generation and the volatility of load, a hybrid probability model of multiple scenarios photovoltaic power generation-load is proposed by considering the occurrence probabilistic of the load and photovoltaic power in different states. The supporting points of the system voltage are found by using voltage sensitivity analysis method, which are taken as the candidate buses of the photovoltaic installation to increase the efficiency of photovoltaic locating. Taking improved voltage profile improvement index (VPII) as an objective function, the locating and sizing models of photovoltaic power generation are built by adding the hybrid probability model of multiple-scenarios photovoltaic power generation-load into power flow equations. In the end, the rationality and effectiveness of the proposed model is verified by taking the IEEE14 radial distribution grid test system as calculation case. The simulation results show that the reasonable choice of locating and sizing of photovoltaic power generations can effectively improve the voltage stability margin of distribution system, increase the voltage stability, and reduce the loss.