Solar photovoltaic(PV) array power generation, as a utilization form of solar energy, has been widely applied in solar generator systems throughout the world. Effective guarantee of PV array normal power generation, rapid and accurate detection of fault location and the prediction of fault occurrence are of great significance. This paper, based on the analysis of solar photovoltaic power generation performance, raises new voltage and current detection method. The original current and voltage detection method can not distinguish the environmental factors which causes the decrease in power generation capacity. This new test method can overcome such defect, and can accurately judge the location where cell array fault occurs; this technology is very important to safe and reliable operation of solar photovoltaic generation system and the improvement of power generation efficiency.