Abstract: The large-scale application of the Dianhong operating system provides a new technological path for intelligent operation and maintenance of digital substations. Based on the full chain architecture of the power Internet of Things, an end-to-end interconnection system covering the perception layer, network layer, platform layer, and application layer is constructed, integrating core scenarios such as mobile work workstations, intelligent terminal remote control based on WAPI, remote work permits, and experimental data collection and analysis. The system deployment results show a significant improvement in interoperability between devices, and the efficiency of intelligent operation in substations has been effectively improved, providing a reusable technical paradigm for the large-scale promotion of the power Internet of Things.