Abstract: Baodian Coal Mine of Yangzhou Mining Group has reformed the decentralized power supply system by using AUTOCAD and network technology. The work includes the monitoring or electrcity network status and insulation of mining area substation, setting up on surface mechanical and electrical management network, bringing surface 35 kV microcomputer monitoring into mine WINDOWS NT to achieve microcomputer monitoring and management of whole mine substations on surface and underground. And valuable exploration has been made in underground on line monitoring.