The invention provides a self-adaptive power distribution network operation mode fault locating and isolating system and a working method thereof, relates to the technical field of electric power system distribution network automation, and particularly relates to the self-adaptive power distribution network operation mode fault locating and isolating system and the working method thereof. According to the self-adaptive power distribution network operation mode fault locating and isolating system and the working method thereof, radiation type and hand-in-hand ring network and other simple network frames can be handled, network type complex network frames can also be handled, and the system is self-adaptive to fault processing of all the operation modes in the network frame range, and the response speed is fast, the stability is high and locating is accurate. Intelligent terminals include a logical operation module, a logical judgment module, an instruction module and an isolation operation module. The logical operation module is connected with a voltage sensor and a current sensor through an analog-to-digital converter. The isolation operation module is connected with an isolation switch. The system is high in degree of freedom and large in range of application.