Impact of Digital Innovation on Regional Synergistic High-Quality Development

Digital innovation constitutes the core determinant of sustainable digital transformation and functions as a pivotal driver of regional high-quality economic development. As a strategic node in China’s urban agglomeration framework, the Guangdong–Fujian–Zhejiang Coastal Urban Agglomeration plays a critical role in regional synergistic high-quality development. This study examines how digital innovation impacts the coupling coordination of high-quality development in the urban agglomeration. The results show: (1) Synergistic high-quality development shows a steady downward trend in the research region with substantial coordination potential. (2) “Gradient disparity” exists, primarily driven by inter-regional Gini coefficient contributions. (3) Overall coupling coordination remains at the antagonistic stage with significant convergence tendencies. (4) Lack of robust central city and centripetal force hinders effective spatial radiation. Driven by the core-periphery spatial differentiation, the short-run dominance of digital innovation’s polarization effect undermines the coordination level of urban agglomerations through scale expansion, structural optimization, and technological empowerment. It requires vigilance against Yangtze and Pearl River Delta siphoning effects. This study provides theoretical and practical implications for promoting digitally driven, synergistic, sustainable, and balanced high-quality development, as well as for optimizing policy frameworks in the new era.