[Objectives] The conservation of bird diversity is not only a primary goal of ecological restoration but also an important indicator for guiding and evaluating its effectiveness. As one of the three most polluted lakes in China, Dianchi Lake has undergone extensive wetland restoration in recent years. However, few researchers have systematically investigated its bird diversity to guide effective conservation and further restoration efforts. Therefore, this study synthesizes a decade of field surveys on bird diversity, integrating findings from literature and citizen science of Dianchi Lake. A key objective is to analyze the ecological characteristics of the avian community, thereby generating critical, actionable insights to direct the future wetland restoration efforts in this region. [Methods] The methodology was structured as a two-stage analytical process. Initially, a comprehensive avian checklist for Dianchi Lake was compiled by integrating a decade of field survey data with existing scientific literature and citizen science records. Subsequently, the ecological requirements of the avian community were assessed through a multi-faceted analysis of the species diversity, residency patterns, ecological traits, and trophic niche structure. [Results] A total of 363 species were recorded, comprising 126 waterbird species and 237 forest bird species. Among them, 75 species are classified as nationally protected or are listed as endangered on national or global Red Lists (Fig. 3, Electronic appendix 1). Analysis of residency patterns revealed that waterbirds were predominantly passage and winter migrants, while forest birds were predominantly residents and passage migrants, with the majority of species in both groups being rare or occasional (Table 3). In terms of ecological guilds, the waterbird community was dominated by grallatores, particularly small shorebirds, whereas forest birds were primarily passeres. Correspondingly, the primary trophic niches were aquatic predators for waterbirds and invertivores for forest birds (Fig. 4). [Conclusion] The avian community of Dianchi Lake is characterized by high diversity in residency patterns, ecological guilds, and trophic niches. However, the community structure is uneven, dominated by a small number of dominant and common species alongside a large proportion of rare and occasional visitors. In light of the aforementioned findings, the establishment of a continuous, year-round monitoring regime for avian population dynamics is advised, with specific attention directed towards migratory and overwintering seasons. Furthermore, the construction of a continuous bathymetric gradient extending from swamp zones to deeper waters, alongside the enhancement of the structural complexity and diversity of the aquatic and hygrophilous vegetation community, is advocated to satisfy the specific ecological niches of the avian assemblage.