The competence to change work roles is a key factor for individuals in achieving a successful work role transition. In this study, we analyzed in-depth interview data of 31 “double-qualified” teachers and related teaching managers in higher education institutions using the grounded theory method and constructed a model of the structural dimensions of teachers’ work role transition competence and its generation mechanism. The model was also interpreted using work role transition theory, the Job Demand–Control–Support (JDCS) model, and employee learning theory. The research results show that the work role transition competence of teachers in higher education institutions is mainly composed of four dimensions: old role detachment, psychological adaptation, new role cognition, and resource reserve capacity; the four factors of work role demand (initiation factor), role breadth self-efficacy (internal contextual factor), social support (external contextual factor), and individual learning (direct factor) follow the theoretical logic of “demand–context–learning–competence” to influence the formation of work role transition competence. This study enriches and expands the theory of work role transition, which can help teachers in higher education institutions to effectively apply it in their work role transitions and can help higher education institutions to further improve the corresponding norms of human resource management practice.