The utility model discloses a distribution system trouble on -line monitoring system, it includes the monitor terminal who is used for detection line short circuit and earth fault, its backbone and department of branch line branch of installing at the circuit has wireless communication module, be used for the wireless communication controller of wireless collection monitor terminal data, it is installed in having solar charging device's block terminal, the signal output part of its signal input part wireless connection monitor terminal wireless communication module, a communication management ware for collecting and handle whole data of being qualified for the next round of competitions, the side of being qualified for the next round of competitions in every transformer substation is installed to communication management ware, the signal output part of its signal input part wireless connection wireless communication controller, its signal output part wireless connection background system. The utility model discloses simple structure, it is convenient to the detection of power line information, can provide accurate trouble information and fault location, make the staff in time make corresponding processing. The utility model is suitable for a china electric power system's circuit monitoring.