The invention discloses a sulfur hexafluoride gas leakage monitoring system based on the internet of things. The system comprises a detection unit, a main controller, a cloud platform management unit,a user terminal and a plurality of alarm units and fans, wherein the detection unit is used for collecting gas concentration information and feeding back the gas concentration information to the maincontroller; the main controller controls the alarm units and the fans to realize alarming and exhausting; meanwhile, in combination with time, the gas concentration information and alarming and exhausting information are sent to the cloud platform management unit to be stored and are sent to the user terminal; and a user performs lookup management through the cloud platform management unit through the user terminal. The corresponding acousto-optic alarms and fans can be started through monitoring data, so that the gas concentration in space is reduced, the risk of entering the space by working personnel is reduced, the centralized and one-stop management of system equipment and data is achieved, and a solid foundation is laid for establishing an automatic, informationized, networked and normalized SF6 detection alarm type device based on the internet of things.