The national top-level institutional design for differentiated reform of higher education institutions has been realized through policy implementation, in which the diffusion of policy innovation at the provincial level constitutes a key process influencing the outcomes. Currently, the provincial policies for differentiated reform of higher education institutions exhibit a trend of convergence. This reflects a range of issues, including insufficient comprehensive consideration of higher education institutions as core actors in policy design, weak policy innovation that fails to reflect local characteristics, inadequate capacity to alter the conventional development paths of universities, low alignment between institutional development and provincial goals, and a lack of vitality in the overall planning of differentiated development of higher education institutions by provincial governments. These convergent characteristics reflect not only the adaptability of the institutional framework itself but also the outcome of interactions within the broader institutional environment. The underlying logic of policy innovation diffusion tends to induce homogeneity, which manifests in practice as decentralized governance during transition and intensified performance-based accountability. These mechanisms further promote a competitive-cooperative dynamic among provinces and deepen convergent tendencies. This study recommends that, while adhering to the general principles of policy innovation diffusion, efforts should be made to develop policy interpretations that integrate both national uniformity and provincial specificity. It is also essential to establish a differentiated evaluation system that incorporates both specialization and local contextualization, so as to stimulate endogenous motivation in the differentiated reform in higher education institutions at the provincial level.