Baiyangdian Wetland is located in Xiong'an New Area, with important ecological functions and special strategic position. For a long time, the Baiyangdian Wetland has gradually shrunk and even dried up under the combined effects of human activities and climate change. It is of great significance to study the carrying capacity of ecological and environmental in the Xiong'an New Area by understanding the ecological function and regionalization of the Baiyangdian Wetland ecosystem. This is one of the current widespread concerns and urgent problems to be solved. In order to meet the needs of ecological protection and management of Baiyangdian Wetland, this study evaluated and regionalized the ecological functions by combining methods of field survey, remote sensing, and comprehensive evaluation. Images of Landsat MSS/TM/ETM+/OLI in 1975-2018 and GF-2 PMS in 2017 and 2018 were acquired to analyze land use/land cover change. Firstly, on the basis of clarifying characteristics of natural environment and main ecological problems of Baiyangdian wetland, the indicators system was constructed for evaluating ecosystem service function and ecological sensitivity. Secondly, the ecosystem service functions were evaluated from five aspects:supplying of aquatic products, supplying of aquatic plants, climate regulation, biodiversity maintenance, and improvement of water quality. The ecosystem sensitivities were evaluated from three aspects:water pollution, wetland changes as well as importance of natural and cultural values. Finally, based on results of evaluation, the Baiyangdian Wetland was initially regionalized into seven first-level ecoregions and nineteen second-level ecoregions. We combined ecological processes and impacts of human activities into ecological regionalization, reflecting the dynamic characteristics of human-land relationships in Baiyangdian Wetland. The results covered spatial and temporal characteristics of the ecological environment, which could help manager to make decisions for the ecological protection planning in the future. We suggested that regionalization-oriented measures should be formulated according to the ecoregions characteristics in the process of implementing project of ecological environment protection and management in Baiyangdian Wetland.