In accordance with requirements of unified space-time model of mine Internet of Things, underground power monitoring and management system based on GIS was developed. The system sets up internal structure model and interconnected geographic topology model of devices of distribution points and power subsystems, translates CAD drawings of underground power system into GIS topology diagrams, and combines graphics software with database to describe and manage parameter attributes and geometric topological relations of various power equipments. The system uses multi-world spatial associated expression and realizes a map management of underground distribution grid and its assets.