Service learning, as a practice that links community service with learning activities, is gaining popularity in teacher education as an experiential educational approach. However, a deeper understanding of teachers' motivation in service learning is required to improve teacher retention and commitment. Utilising the Factors Influencing Teaching Choice (FIT-Choice) framework, this empirical study attempts to understand the reasons why student teachers volunteer in rural China and the differences between volunteer and non-volunteer teachers in their motivation and perception of the profession. The sample includes 201 volunteer and 812 non-volunteer student teachers. The results validate the FIT-Choice scale for Chinese volunteer student teachers and reveal significant differences in most motivational factors between the two groups. Volunteer student teachers perceive the teaching profession as less demanding and more rewarding than their non-volunteer counterparts. Moreover, they express greater satisfaction with their career choice. This research advocates for volunteer teaching as a valuable pedagogical approach to teacher education and a means of addressing teacher shortages.