The utility model discloses a distribution fault monitoring system. The system comprises at least one wireless distribution monitoring sensor which is connected with a distribution transformer through an optical fiber and is used for acquiring the fault information of the distribution transformer, a concentrator which is connected with the wireless distribution monitoring sensor through a wireless sensor network and is used for receiving the fault information acquired by the wireless distribution monitoring sensor, and a monitoring main station which is connected with the concentrator through a wireless optical network and is used for receiving the fault information received by the concentrator. According to the utility model, by comprehensively using the respective characteristics of the optical fiber, the WSN network, a power line and the passive optical network, the problems of difficult routing, large line changing work quantity, easy line damage, immobility, unstable operation and poor reliability of the existing distribution fault monitoring network routing are solved; and the system is suitable for distribution fault monitoring.