Background <p>Among the growing migrant population in China, older adults who choose to migrate with their children to provide caregiving for grandchildren have attracted scholarly attention. This study explored what challenges they have experienced in sociocultural and psychological adaptation process in host cities and what social support was effective based on the adaptation theory and stress and coping theory.</p> Methods <p>The study employed a mixed-method study. Twenty-five older urban relocators participated in interviews and 376 older migrants completed a set of surveys. Interview responses were analysed with the thematic analysis approach and quantitative data were examined with linear regression analyses.</p> Results <p>In the qualitative phase, interviews indicated that older urban relocators depended on not only social support from host cities, but also support from their hometown to deal with adaptation difficulties, so whether and how these types of support predicted different dimensions of adaptation was examined later through a questionnaire. In the quantitative phase, results of a survey showed that support from co-living children and new friends in the host city was the most effective protective factor to promote both sociocultural and psychological adaptation and support from community services was positively associated only with sociocultural adaptation.</p> Conclusion <p>These findings provide a better understanding of how older urban relocators experienced new lives in host cities, and they could guide professionals to provide older adults with necessary support and promote older adults’ adaptation to the current community.</p>