Abstract: A fault detection and positioning system for a cell panel in a large-scale photovoltaic array, includes a first photovoltaic panel fault detection and positioning system, a second photovoltaic panel fault detection and positioning system, and/or a third photovoltaic panel fault detection and positioning system. The detection and positioning system can detect faults of panels in the photovoltaic array in real time, especially accurately positioning a photovoltaic panel in which a fault occurs; the number of sensors can be minimized, so that the detection costs can be reduced; and the system can be easily implemented and mounted in existing power stations.