This low voltage reactive power device is suitable for reactive power automatic compensation in the 50Hz, 0.4kV urban distribution network. It adopts a series of leading domestic technologies and the latest components, integrating reactive power compensation and grid monitoring. It not only can compensate for reactive power loss in the grid, improve power factor, and reduce line loss, thereby enhancing the load capacity and power supply quality of the grid; but also can real-time monitor the three-phase voltage, current, power factor and other operating data of the grid. It can complete comprehensive management such as monitoring, analysis processing, and report output for the entire low-voltage distribution line, providing first-hand data for the scientific management of low-voltage distribution lines.