<p>The aim of this study is to investigate the influence of multiple jobholding (MJH) motivations on the career sustainability of MJHers. Based on self-determination theory and conservation of resources theory, this study constructs a chain mediation model to capture the impact of MJH motivations on career sustainability under the push-pull framework, focusing on the mediation roles of proactive behavior and thriving at work. Hierarchical multiple regression and bootstrap methods are employed to carry out empirical tests based on the 427 questionnaire data of MJHers. The study findings indicate that though both pull and push motivation are positively associated with proactive behavior, thriving at work, and career sustainability, MJHers with pull motivation exhibit more proactive behavior, higher thriving at work, and stronger career sustainability as compared to those with push motivation. Meanwhile, proactive behavior plays a mediating role between push/pull motivation and career sus-tainability. In the same vein, thriving at work also plays a mediating role between push/pull motivation and career sustainability. Furthermore, proactive behavior and thriving at work play a chain mediating role between push/pull motivation and career sustainability. These findings enrich the existing em-pirical research gap related to MJHers by elucidating whether and how work motivations enrich the career sustainability of MJHers from motivation and resource perspectives. Moreover, for organiza-tions, this study highlights the critical role of MJH motivations in shaping career sustainability.</p>