<p>Doctoral students are at a critical stage in developing their research capabilities. This study employs causal inference methods and a 10-year panel dataset of Chinese doctoral students to explore the impact of non-degree international academic mobility on doctoral students’ research collaboration and output. The findings reveal that international mobility expands doctoral students’ international collaboration networks and increases both the quantity and quality of their internationally co-authored output. These effects are partially mediated by the expansion of international collaboration networks. Moreover, male doctoral students in management science from low-prestige institutions gain more benefits from international mobility than female doctoral students in economics from high-prestige institutions. Finally, long-term mobility, particularly that occurred from 2013 onward, is more effective than short-term mobility prior to 2013 in expanding international collaboration networks and improving international collaborative output.</p>