Abstract: There was great water resources contained in the water area caused by the coal mining subsidence in Huainan Mining Area.In order to protect and ratio nally utilize the water resources in the subsidence water area, a ecological-water quality numerical model was established to predict the water quality evolution of the s ubsidence water area.The finite difference method was applied to the dispersed, ecological dynamics phase and diffusion phase decoupling treatment of the model.The seven indexes of NH+4-N、NO-2-N、 NO-3-N、 DO、 BOD、 PO3-4 (phosphate) and CHL (chlorophyI) were selected as the water quality variations. The model was appli ed to the simulation calculation on the water quality of the different age water areas in Huainan Zhangji Mine and Guqiao Mine.The results showed that the pollutants in over 6years subsidence water area would be steadily reduced.In the year of 2020, the simulation densities of the seven water pollution indexes in No.1 subsidence wat er area of Zhangji Mine were predicted as 0.44, 0.004, 0.008, 8.19, 4.18, 0.034 and 0.02 mg/L individually and the water quality would become better.