In order to achieve sustainable development of water resources, the paper combined prediction and decision function of WEAP to simulate and set up the scheme of water allocation and used large-scale systems hierarchical and fuzzy optimization theory to propose a model of evaluating water resources allocation scheme. The paper designed three kinds of water allocation program according to the status of water resources utilization of Jinchang, and took the maximum coefficients of sustainable development as the objective function to choose and evaluate the best solution by comprehensively considering the sustainability, coordination and fairness of water resources development. The results showed that adjusting industrial structure，reducing watered field，programming exotic water and implementing water-saving technology are the feasible measures for Jinchang city to achieve sustainable development of water resources.