In order to visualize the complex spatio-temporal relationships and multi-source heterogeneous data in large-scate power grids, a visualized architecture of power grid for the dispatching and control cloud is proposed. For the visualization of the full-scene varying from specific equipment to grid overview, the full-state of life cycle from history to the future and the full-information including both elements and topics, a four-layer framework is adopted, which is composed of the grid diagram, station diagram, primary equipment diagram, and secondary equipment diagram. This complex architecture allows the illustrations of full-scene grid, full-state grid and full-information grid, including the power system characteristics, operation trajectories and real-time information to become thoroughly descriptive in the areas of full-scene grid, full-state grid and full-information grid. On this basis, the key technologies to realize the visualized power grid are studied. Based on the correlation relationship between electrical relationship and object-oriented model, the visualized correlation map is automatically constructed to comprehensively display the composition and operation of the power grid from multiple levels of scene, state and information, so as to support major applications including real-time operation, operation efficiency analysis, equipment failure analysis, and equipment examination analysis, etc. © 2022 Automation of Electric Power Systems Press.