With rapid economic development and expansion of urban boundaries, increasingly damaged wetland resources have seriously threatened the ecosystem. The study of eco-environmental requirements of wetlands is not only the basis of water resources allocation in development and utilization, but also for creating a sustainable system to maintain and improve the overall ecosystem. In this study, we used the Shuangtaizi Estuary Wetland as our study area. The breakdown of wetland cover types was extracted based on multi-source remote sensing data, providing the graphic database for ecological water requirement calculation. According to the characteristics of the Shuangtaizi Estuary Wetland ecosystem, the methods of quantifying the components of ecological water requirements were determined. The results showed that the optimum ecological water requirement of the total wetland was 239 million m3. The minimum, 75th percentile frequency, and 95th percentile frequency water requirements were 670 million m3, 921 million m3, and 1,078 million m3, respectively.