The noise pollution, habitat loss, and human disturbance caused by urbanization have led to damage in bird communities. Research on the relationship between urbanization and birds predominantly focuses on highly urbanized areas, with few studies in underdeveloped urbanized areas. Given the greater stability of the bird community during breeding season, it was chosen for this study. Here, we conducted bird surveys along the urban-rural continuum by utilizing 150 line transects within a 51385 km2 area from June to August in 2022 and 2023, aiming to explore the impact of urbanization on bird species diversity and functional traits during the breeding season in the Huanghuai Plain of China. We found that species diversity and functional traits had significant differences among three habitats (i.e., urban, suburban, and rural). Additionally, the urbanization synthetic index had significant negative correlations with species richness and the Shannon-Wiener index, while having no significant correlation with functional traits. We then assessed that the environmental noise, the distance to the county center, and the proportion of building area within a 250-meter radius were critical factors affecting species diversity, as well as environmental noise and the distance to the county center being the best predictors for functional traits. Urban birds preferred to construct nests at crown, and the diets of them tended to be omnivorous. Our study highlights the importance of the environmental noise, the distance to the county center, and the building index for the protection of urban birds in Huanghuai Plain. The research findings filled the gap in the study area regarding the relationship between urbanization and avian communities based on the urban-rural continuum.