Many problems, such as the shortage of water resources and the low operating efficiency of water project, are ubiquitous in an irrigation district with multi-water resources. Therefore, it is significant and necessary to implement joint dispatching of multi-water resources to alleviate water shortage and promote the synergy ascension of water resources productivity. Taking Heping irrigation district in Heilongjiang Province as an example, a fuzzy multi-objective programming for multiwater resources optimal allocation model was constructed. The proposed model was capable of increasing water net benefit and decreasing water-use amount simultaneously, which would improve the effective allocation of multi-water resources of Heping irrigation district. Fuzzy multiobjective programming with nonlinear membership functions was adopted to solve the model, and the optimal water allocation schemes under different flow levels and water sources were obtained. Results showed that water shortage existed in each growth period of rice under each flow level, and more water should be transferred from Liuhe reservoir under low flow level to guarantee the minimum water requirement. Water were allocated to rice in the order of water diversion project, water lifting project and well irrigation project to ensure the total benefit of Heping irrigation district. The stability of the multi-objective model operation under different scenarios was obtained and analyzed in detail. Water allocation of water diversion project was relatively stable, while water allocation of well irrigation project had higher sensitivity for nonlinearity of membership function of the objective function under low flow level. The developed model can effectively allocate multi-water resources to the different growth stages of rice, which would provide reasonable decision schemes for the corresponding administrative departments.