Single-phase two-wire rail smart meter, can realize two-way communication through RS485 for reading and setting power data and parameters. The built-in high-quality magnetic holding relay can carry out user-side load management, and the backlight can be lit through the button to facilitate viewing data at night; The metering method can be set to meet the requirements of bidirectional measurement. The meter has multi-functions and compact structure, and is suitable for various application scenarios such as residential households, industrial fields, new energy charging stations, and renewable energy power generation.