Smart measuring switch is an intelligent molded case circuit breaker integrating ordinary molded case circuit breaker, metering analysis, and IOT communication. It is suitable for three-phase, four-wire, neutral point directly grounded power distribution network with AC 50Hz, rated current 250A (100A-250A adjustable), rated insulation voltage 800V, and rated working voltage 400V. It has a number of IOT sensing functions such as dual-mode communication, high precision alternating current sampling, power supply relationship topology identification, metering boxes management, power theft early warning, power outage reporting, line loss analysis and judgment, terminal temperature detection, fault automatic diagnosis and other IOT sensing functions, and it has the functions of overload long time delay, short circuit short delay, instantaneous short circuit , over/under voltage and phase failure protection.