The paper built the supply and demand model of water resources which comprised the subsystems such as water resources supply, domestic, industry, agriculture, ecology and environment, public water demand by using system dynamic software STELLA to simulate the supply and demand situation of water resources in Anhui from 2012 to 2030.The simulation result is good.The sensitivity analysis of parameters shows that the model is robust to the change in model parameters related to the growth rate of industrial added value, water demand of industrial added value per 10,000 Yuan and effective irrigation coefficient of farmland. The three different scenarios (scenarioⅠ, scenarioⅡ, and scenarioⅢ) of water shortage conditions were proposed.The scenarioⅠ and Ⅱdelayed the time of water resources shortage compared with current development mode.While scenarioⅢcan solve the contradiction of water shortage in the coming 18 years by pursuing the aim of stable economic growth and ecology-friendly. In the end, the paper put forward some measures to deal with the problem of water resources which can provide reference for alleviating the contradiction of water resources shortage and the optimum allocation of water resources in Anhui.