<p>In contemporary work contexts, self-employed side hustles have become a widespread means for individuals to pursue independent ventures alongside traditional employment. These hybrid work arrangements offer flexibility and opportunities for self-development, while simultaneously blurring the boundary between being an employee and an entrepreneur. Despite their growing prevalence, the psychological mechanisms that transform side-hustle experiences into intentions for full-time entrepreneurship remain underexplored. Drawing on Social Cognitive Career Theory and Possible Selves Theory, we propose a moderated mediation model in which entrepreneurial self-efficacy functions as a key cognitive mechanism linking side-hustle success to primary-job exit intention, while future work self-salience amplifies this indirect effect by shaping how individuals interpret and internalize their achievements. Two waves of survey data from 329 Chinese hybrid entrepreneurs support the proposed hypotheses. The findings position side hustling as a psychological incubator for entrepreneurship and underscore the importance of a salient future self in transforming mastery experiences into entrepreneurial aspirations. Side hustles should therefore be understood not only as income-generating activities but also as career-relevant experiences that can shape readiness for entrepreneurial transition.</p>