The invention relates to the technical field of power systems, in particular to a visualization application system for power grid planning, comprising a power grid GIS platform, a business port and a visualization engine; the visualization engine establishes a communication connection with the power grid GIS platform through the business port; the visualization engine includes a development graph model Corresponding unit, visual interaction unit, one-picture three-state unit, deepening power grid analysis unit and deepening space analysis unit. On the basis of the power grid GIS platform, build a visualization engine of the intelligent planning system based on the Internet of Things; realize automatic analysis on the statistical stage map, efficient design on the planning stage map, intelligent decision-making on the planning stage map, and dynamic tracking on the construction stage map. Develop visual work engines of different professions; realize the whole business process of distribution network planning, such as simplifying data collection and management, status analysis and diagnosis, load forecasting and checking, intelligent site selection and route selection, planning scheme comparison and demonstration, planning results display, etc., and deepen power grid analysis and spatial analysis.