Based on quantitative analysis of a regional water resources system, a dynamic model was constructed for the water resources security system in Jiangsu Province. A simulation case study was conducted. The results show that Jiangsu Province will have water resources supply and demand security problems after the year 2018. Through quantitative analysis, four dynamic factors that influence the water resources security system of Jiangsu Province were determined, and six kinds of solutions were designed. Through comparison of these solutions, the comprehensive solution was determined to be the optimum solution for the sustainable utilization of water resources. In addition, corresponding recommendations for sustainable development of the water resources in Jiangsu Province are proposed.