The utility model discloses a state monitoring system of a ring main unit. The state monitoring system of the ring main unit comprises a solar cell panel, a DC/DC convertor, a storage battery pack, a temperature sensor, a humidity sensor, a current sensor, a voltage sensor, a smoke sensor, an A/D convertor, a digital signal processor and a single chip microcomputer. The temperature sensor, the humidity sensor, the current sensor, the voltage sensor and the smoke sensor are respectively connected with the A/D convertor; the A/D convertor, the digital signal processor and the single chip microcomputer are sequentially connected; the solar cell panel, the DC/DC convertor and the storage battery pack are sequentially connected; and the storage battery pack is respectively connected with the digital signal processor and the single chip microcomputer. According to the state monitoring system of the ring main unit, solar energy is converted to electricity and stored, so that real-time electricity supply is achieved and the continuous and stable operation of the monitoring system is ensured.