The disclosure provides an MQTT-based distribution Internet of Things system and a method thereof. The system includes: a sensing ring including a plurality of data acquisition and monitoring devices and a sensing control module provided in a distribution network; an application ring including a plurality of application servers and an application control module; a communication ring including at least one communication module, each communication module being connected with the application control module and a corresponding sensing control module respectively. The application ring is configured to issue an application request, so that the sensing ring controls a distribution device in the distribution network according to the application request and acquires device data of the distribution device, and the sensing ring feeds the device data back to the application ring; and/or the sensing ring is configured to sense and acquire the device data of the distribution device, and send the device data to the application ring, so that the application ring performs data management, data processing, data analysis, data monitoring and data pre-warning on the device data. The method has a beneficial effect that the constructed distribution Internet of Things system is simpler.