Topography is an important element in the design of green space. Plant configuration adapted to microtopography will change the habitat function of green space and affect the biodiversity in it. In order to explore the relationship between bird diversity and habitat characteristics in campus green space in a mountainous environment, this study selected five types of campus habitat in Chongqing University Area A from August 2018 to April 2019; the sampling line method and the sampling point method were used to investigate the birds in the campus. The results showed that: (1) A total of 24 species of birds were found in Area A of Chongqing University, belonging to 5 orders, 18 families and 23 genera. The composition of bird fauna showed obvious Oriental characteristics, and resident birds were the main part of the composition of birds on campus. (2) The species diversity of birds in the five habitats from high to low was: water and lakeside green land (3.126) > slope land (2.742) > road green space (2.556) > open forest land (2.386) > terrace (1.940). (3) Bird diversity was affected by multiple factors, such as vegetation richness, vertical structure of vegetation, spatial form and spatial complexity, and human disturbance. Based on this, some suggestions on campus ecological construction are put forward in order to provide a reference for campus ecological construction.