<p>Urban vitality is a critical indicator of sustainable urban development and long-term growth. This study investigates the spatial–temporal evolution of urban vitality drivers in Kunming, China, across three periods: 2014, 2018, and 2022. Using geospatial data, normalized densities of catering points of interest and nighttime light were analyzed through spatial autocorrelation, standard deviation ellipse, geographic detector, and geographically weighted regression methods to reveal dynamic patterns and mechanisms. Results show that urban vitality exhibited clustering characteristics and directional shifts over time. In 2014, transportation accessibility, including time to bus stops and subway stations, was the dominant factor, emphasizing foundational infrastructure. By 2018, the city’s rapid northeastward expansion highlighted parking accessibility and public facilities density as key drivers, reflecting increasing reliance on private vehicles. By 2022, urban vitality rebalanced spatially, with built environment factors such as building density and park accessibility playing a more significant role. The findings highlight the spatial heterogeneity and dynamic interplay among transportation systems, population density, and built environment indicators. While transportation factors declined in influence, built environment and green space accessibility gained prominence over time. This study underscores the necessity for multidimensional, adaptive urban planning to sustain vitality and suggests integrating additional factors, such as environmental quality and social equity, in future research. These insights provide valuable guidance for achieving balanced and sustainable urban development in Kunming and beyond.</p>