Single-phase smart IoT power meter is a new generation of high-performance and high-configuration three-phase smart power meter that fully meets the requirements of IR 46 standard. The single-phase smart IoT power meter adopts modular design, that is, the metering core is independently separated from the management core, and supports different expansion modules. Through the multi-core module design and SPI isolation scheme, it can meet the different needs of users to complete a series of diversified functions such as control, communication and metering. At the same time, as the measurement and management function operate independently, it greatly improves the accuracy and stability of the measurement function.