<p>With the acceleration of urbanization and the increase of people’s mobility, the daily life of urban residents has been undergoing profound changes. Existing studies on place attachment have mainly focused on static perspectives that centered on the spatial dimensions, while process-oriented research examining how individuals construct, perform, and negotiate place attachment through their daily activities remain limited. Using Guangzhou as a case study, this research develops a dynamic analytical framework for understanding place attachment from the perspective of individuals’ everyday activity spaces. Drawing on individual-level mobility-activity data, and employing statistical analysis, Random Forest modeling, and SHAP interpretation, the study uncovers the temporal and spatial fluidity of place attachment and explores the nonlinear mechanisms underlying its formation. The results show that individuals’ place attachment tends to strengthen during nighttime and weekends, with higher emotional bonds observed in residential communities than in workplaces. Moreover, social capital, income level, and activity characteristics all exhibit notable threshold effects when influencing place attachment as key determinants. This study advances place attachment research by introducing a dynamic, activity-based perspective and provides both theoretical insights and empirical evidence. It also proposes a methodological framework that could provide a useful reference for future research on the evolving dynamics of human–place relations in an increasingly mobile urban world.</p>