The EFDC (the environmental fluid dynamics code) model was developed by John of the Virginia Institute of marine science at the College of William and Mary The three-dimensional surface water quality mathematical model developed by Hamrick et al. Can simulate the hydrodynamics and water quality of rivers, lakes, reservoirs, wetland systems, estuaries and oceans. It is a multi parameter finite difference model. After nearly 20 years of development and improvement, the model has been widely used in universities, government agencies, environmental consulting companies and other organizations, and has been successfully used in the study of more than 100 water regions in the United States and other European countries. In China, it has been applied to the water quality simulation of Dianchi Lake in Yunnan Province, the hydrodynamic simulation of two rivers confluence in Chongqing, the nutrient simulation of Miyun reservoir, and Wuliangsuhai, Inner Mongolia Regional water eutrophication simulation.