Based on the characteristics of construction control, management and decision-making during the river closure implementation process, the author by analysing technical requirements and practical demands of river closure, proposed the objectives, structure, functions and technical requirements of dynamic decision support system for river closure construction. This system integrates monitoring, controlling, management and decision making of river closure construction, hence ensuring the automation of construction data acquisition, informatization of construction management, as well as scientific decision of river closure construction. In this way, it guarantees the safe and reliable, accurate and controllable, scientific and economic, and punctual river closure process. The application of the system in open channel closure of the Three Gorges and in other projects has manifested that the system plays a significant role in accurate dike advancing process controlling, and in precise and orderly river closure as well.