This study proposes and validates a sequential digital-physical-psychological (DPP) pathway model to explain how social media use facilitates international students' cross-cultural adaptation through behavioral and psychological mediation. Building on media system dependency theory and social learning theory, the model posits that digital engagement (e.g., WeChat interactions) initiates a cascading process: it first reduces barriers to extracurricular activity participation, which subsequently enhances the sense of multidimensional social integration (psychological identification, social interaction, and cultural adaptation). Data from 713 international students at Chinese universities, analyzed via structural equation modeling, confirmed significant direct ([beta] = 0.27, p < 0.001) and chain-mediated effects ([beta] = 0.04, p < 0.001), demonstrating that adaptation progresses sequentially from the digital domain to the physical domain to the psychological domain. The findings challenge parallel-process frameworks such as Ward's ABC model, instead emphasizing the temporal dynamics of digital-era acculturation. By integrating digital pathways into adaptation theory, this study advances a structured framework for understanding technology-mediated intercultural transitions. These findings address critical gaps in acculturation research by integrating digital pathways and temporal dynamics, offering evidence-based strategies for universities to design integrated digital-physical support systems.