Abstract: In order to understand the status quo of waterbird diversity in Hainan Dongzhaigang National Nature Reserve, grasp the seasonal dynamic changes of birds and the trend of changes in different years, and provide scientific basis and technical support for biodiversity conservation and habitat management in Hainan, we conducted a survey from January 2021 to December 2022 by using the zonal synchronous survey and compared with the previous survey data. The results showed that 72 species, 13 families, 6 orders of waterbirds were recorded. A total of 62,703 waterbirds were recorded. The seasonal dynamic changes of species diversity was winter > autumn > spring > summer. There were significant differences in the diversity and seasonal dynamics of waterbird in different habitats, among which tidal mangroves and breeding ponds were the two most important habitats for waterbirds in Dongzhai Harbor. Human disturbance and habitat change may be important factors affecting the survival of wintering waterbirds. It is suggested that conservation measures and ecological restoration strategies should be formulated according to the characteristics of bird communities in different habitats in the study area, ecological restoration should be carried out according to local conditions, and long-term investigation should be insisted.