Multi-functional power instrument is a multifunctional intelligent instrument with programmable measurement, display, digital communication and electric energy pulse transmission and output, which can complete electric energy measurement, electric energy measurement, data display, acquisition and transmission. Multi-functional power instrument is widely used in substation automation, distribution automation, intelligent building, and internal electric energy measurement, management and assessment of enterprises. The measurement accuracy is 0.5 level, which can realize LED field display and remote RS-485 digital interface communication, and adopts MODBUS-RTU protocol. It is applicable to power distribution cabinets and intelligent buildings.