Objective <p>To clarify the mediating role of aging self-efficacy and explore how physical activity and community support influence the subjective well-being of Pre-K–9 teachers in Dongguan, a manufacturing city. The aim is to provide empirical evidence in favor of improving the well-being of local teachers.</p> Method <p>A questionnaire survey was conducted among 1,005 Pre-K–9 teachers in Dongguan City to collect data, which was then modeled and analyzed using the PLS-SEM model.</p> Results <p>Community support, physical activity, aging self-efficacy, and subjective well-being all showed significant positive correlations (<i>p</i> &lt; 0.001); community support (β = 0.263, <i>p</i> &lt; 0.001) and physical activity (β = 0.289, <i>p</i> &lt; 0.001) directly and positively predicted subjective well-being. Furthermore, their positive predictive coefficients for aging self-efficacy were 0.271 and 0.340, respectively (both <i>p</i> &lt; 0.001). The independent mediating effect of aging self-efficacy between community support and subjective well-being was 0.053 (<i>p</i> &lt; 0.001). The chain mediation effect among community support, physical activity, and subjective well-being was 0.032 (<i>p</i> &lt; 0.001). The model explains 47.9% of the variance in subjective well-being.</p> Conclusion <p>Subjective well-being of Pre-K–9 teachers in Dongguan can be directly improved by community support and physical activity. Through the twin mediating effects of aging self-efficacy, they also have an indirect promotional effect that is both independent and chained. These findings provide empirical evidence for improving teacher well-being among Pre-K–9 teachers in Dongguan. They may also offer context-specific insights for manufacturing cities with comparable educational structures and teacher demographic characteristics, although further validation in other settings is warranted.</p>