This study focuses on digital innovation in the nine inland cities of the Guangdong-Hong Kong-Macao Greater Bay Area, exploring the mechanisms of regional collaborative innovation and the flow of innovative resources driven by the digital innovation. Using digital economy-related patent data from 2014 to 2023, a spatial association network of digital innovation is constructed, and complex network analysis methods are employed to examine the network structure characteristics and its dynamic evolution patterns. The research finds that sustained innovation investment has a significant positive impact on economic development, with network scale and degree centrality acting as mediators in this relationship. Additionally, network density and centrality moderate the influence of sustained innovation investment on economic development. This study provides a new theoretical perspective for understanding the mechanisms through which the digital economy empowers regional economic coordination and offers theoretical support for regional policy-making.