Abstract: The increasing of photovoltaic power generation scale has great impact on power systems, which should not be neglected, so simulation study on stochastic production of power grid with photovoltaic power generation is of great significance. In the spatial scale, the multi-state model of a PV-inverter is built by considering dual factors of solar irradiation and component failure with a PV-inverter as a unit. In the temporal scale, different multi-state models are adopted in different time intervals with one day as an interval. With the multi-state model added to stochastic production simulation, equivalent energy function approach is used to calculate such indexes as the amount of power, reliability, economic. Therefore, the capacity benefit and electricity benefit of PV generation are evaluated. In the end, the rationality of the proposed method is verified by examples.