Solar photovoltaic power is a new form of new energy. It is the energy conversion model that change solar energy into light energy. This article is that energy conversion model of solar photovoltaic power generation system was studied. For household photovoltaic power generation systems, the system’s energy conversion is described by mathematical calculation and computer simulation. It makes an intensive study of the process of radiation, battery energy and power conversion during the whole course of the solar photovoltaic power generation.