College teachers now have more opportunities to engage in transnational education as people enter a new era of globalization and the shift toward a knowledge-based society. However, they also face various challenges in social adaptation. It has become a critical issue to enhance the sense of belonging and career resilience of the returnees from universities. By using a qualitative research method with the data from a respective provincial university in China, this study aims to explore the process and influencing factors of the social adaptation of returnees and finds that the social adaptation of returnees has gone through the process of longing, division, adjustment, and integration, which varies with individual and cultural differences. Social adaptation is similar to the swing and vibration of a clock. The working environment is the primary source of adverse cultural impact and ones social network support is negatively associated with social adaptation. Also, self-efficacy and informal social support networks play key roles in the adaptation process. To mitigate the re-entry shock, recommendations include optimizing work environments, providing emotional counseling, and enhancing organizational structures.