Abstract: China's large-scale urbanization has made the recurring urban-design demand to understand both the built environment and its users increasingly important, while multiple digital technologies have advanced in parallel. This interaction is a major line in the contemporary evolution of urban-design science and supports a more human-centered discipline. This paper reviews theoretical changes in urban design and urban-population research, traces the multidisciplinary origins of profiling, and explains the role of digital population profiles in recognizing individuals as subjects, reconstructing the human-city community, and linking large and small data. Planning projects demonstrate multiscale applications and their operational challenges. The paper concludes by identifying future directions in population profiling, intelligent prediction, and digital urban design for human-city symbiosis.