Due to the impact of global climate change and human activities, there are some problems such as ecological water scarcity, water quality degradation, soil salinization, seawater intrusion and so on, resulting in area reduction of Shuangtaizi estuarine wetland. To restore and protect the wetland environment and address the balance of water supply and demand in wetland, this paper used the eco-hydrological coupling model in the eco-hydrological viewpoint, and simulated eco-hydrological processes of Shuangtaizi estuarine wetland from 1981 to 2005. The results showed that: the inter-annual change of the hydrological elements in the wetland showed a decreasing trend, but the reduced coverage was not significant; the annual change showed a single peak curve, mainly in July and August. The natural supplement water was 8.32 billion cubic meters per year in the wet year, which can meet the eco-water demand. The natural supplement water was 6.21 billion cubic meters per year in normal year, which can meet the minimum eco-water demand. Eco-supply capacity was 1.15—3.90 billion cubic meters per year in the low flow year with the natural supplement water being 4.70 billion cubic meters per year. The eco-water demand can be met after the appropriate measures for ecological supplement regulation are taken.