Research on the diversity of bird species in China has limitations in spatial scale. This study used provincial administrative divisions of China as geographic statistical units, employed eBird citizen science data, and introduced the G-F index to quantify and evaluate the characteristics of bird species diversity. Based on this, spatial autocorrelation analysis was used to explore the spatial distribution characteristics of bird species diversity, and a geographically weighted regression model was established to analyze the spatial heterogeneity of factors influencing bird species diversity. The results show that: (1) Overall, the spatial distribution trend of bird species diversity in China gradually decreases from the southeast coast to the northwest inland, exhibiting a spatial pattern of longitudinal band differentiation; (2) The degree of influence of each influencing factor on bird species diversity exhibits obvious spatial differences: temperature factors show a spatial distribution characteristic of higher in the north and lower in the south, the influence of snowfall factors on bird species diversity is mainly limited to northeastern provinces, the degree of influence of hydrological factors on bird species diversity gradually decreases from both sides to central provinces, the influence of vegetation factors on bird species diversity shows a trend of gradually weakening from southwestern provinces to northeastern provinces, and the influence of human activities on bird species diversity exhibits a spatial distribution characteristic of latitude direction aggregation. These research results contribute to enriching the study of bird species diversity and providing scientific basis for bird resource protection and biodiversity conservation.