Waterfront public spaces and urban built environments are focal points in urban planning, yet more scholars need to focus on the coupling relationship between the two. Only through the coordinated development of these two can urban sustainability be promoted. Using vitality as a medium and drawing from the theory of coupling in physics, the study quantitatively analyzes the coupling and coordination degree between the built environment of 62 research units in the Shenzhen Bay waterfront area and the vitality of the adjacent waterfront public spaces. This is achieved by leveraging the population location big data from Baidu Huiyan, and vector data from Amap. The study finds that: (1) The overall coupling coordination degree between the public space vitality and built environment in the Shenzhen Bay waterfront area is relatively high, although the spatial distribution is uneven. (2) The built environment systems and waterfront public spaces of slightly and moderately discoordination units are predominantly in the process of development and construction, which manifests as a need for more completeness in the overall urban development. (3) Research units in an elementary coordination state mainly display that a moderate-intensity built environment has not spurred the vitality of waterfront public spaces. More units in a moderate coordination state show a relative lag in the urban built environment system. (4) Advanced coordinated and optimally coordinated study units are coordinated and co-developed with each other but can have a siphoning effect, leading to a less coordinated phenomenon in neighboring regions.