Abstract: Amid the intensifying impacts of human activities, global climate change, and rising sea levels, the problem of saltwater intrusion in the Pearl River estuary and delta regions has become increasingly severe, posing significant threats to water supply security. Since 2004, the Pearl River Water Resources Commission has been continuously advancing the application of information technology in emergency water dispatching for suppressing saltwater and replenishing freshwater. This paper reviews the construction history of key information technology projects such as the Pearl River Hydrological Monitoring and Forecasting System and Decision Support Data Center, the Flood and Drought Control Command Systems (Phases Ⅰ and Ⅱ), and the Pearl River Main Reservoirs Unified Dispatching Information Management System. The paper summarizes the achievements in monitoring and sensing, data resources, professional models, application systems, and other aspects. It also analyzes how information technology at various stages has supported and transformed emergency water dispatching for suppressing saltwater and replenishing freshwater in the river basin, and looks forward to the role of new-generation information technology in significantly enhancing the unified dispatching of water resources.