Under the premise that targets of the reservoir’s original flood control and water supply were unaffected, in order to reduce the influence of reservoirs on river ecosystems, in allusion to the situation that the scheduling results satisfied the constraint of minimum ecological flux rather than the appropriate ecological flux, a model to solve ecological scheduling of Nierji reservoir under the condition of incomplete ecological constraints was proposed. The model was based on the scheduling results of constraints of the minimum ecological flux, the solving method of non-sufficient ecologically constrained flux approached the constraint of appropriate ecological flux step by step, and by introducing relaxation variables, the firefly algorithm (FA) was used to optimize the scheduling process which led to the establishment of the relation curve between the degree of the ecological assurance and the generated energy and the confirmation of the optimal equilibrium point under the restriction of the non-sufficient ecological flux by the Tennant evaluation through comparing the Kmin with Kmax-1 methods. The results showed that according to the non-sufficient ecological constraint flux inquired by the used model, the ecological water consumption and the minimum ecological constraints could be increased by 4.415 billion m3, 3.655 billion m3, 5.596 billion m3, 4.626 billion m3, 3.790 billion m3 and 5.481 billion m3, respectively, in the six cases when compared with low flow years and normal years. It was indicated that there was still much room for ecological flow restriction, therefore, when the scheduling results satisfied the constraint of the minimum ecological flux rather than the appropriate ecological flux, it was inappropriate to select result of the constraint of the minimum ecological flux as the scheduling scheme;according to the established relation curve and Kmax-1 method, the degree of ecological guarantee of optimal scheduling scheme under six constraints were 60%, 80%, 40%, 60%, 70% and 70%, respectively and their generated energy were corresponded to 0.60657 billion kW·h, 0.60312 billion kW·h, 0.68513 billion kW·h, 0.66796 billion kW·h, 0.59682 billion kW·h and 0.67859 billion kW·h. In conclusion, the new scheduling model could effectively solve the problem of ecological scheduling under this kind of circumstance, improve the degree of ecological assurance, ensure certain economic benefits and provide a more reasonable scheduling approach for decision-makers and new ideas for these issues.