In an era marked by the rapid ascension of the global digital economy, the digital innovation ecosystem has emerged as a vital conduit for businesses to pursue digital innovation endeavors and enhance their core competitiveness. This paper marries the theoretical discourse and empirical analysis of digital innovation ecosystem theory with modular theory, systematically expounding the concepts of digital innovation ecosystems and modularity, as well as elucidating the design principles of a modular digital innovation ecosystem. It delves into the characteristics and design processes of modularity and dissects the collaborative mechanisms underpinning the Apollo digital innovation ecosystem. Moreover, employing a modular perspective, it empirically scrutinizes the Apollo digital innovation ecosystem to clarify the framework constituted by modularity, the symbiotic operation among the ecosystem modules, and the collaboration within the system’s internal modules. This study embarks from the vantage point of digital innovation ecosystems and modularity to offer an in-depth explanation of the collaborative mechanisms within the Apollo digital innovation ecosystem. It not only broadens the methodological horizons for research on digital innovation ecosystem theory but also delineates, from a practical application standpoint, the modes of collaboration between the ecosystem’s modules. In the process of exploring the collaborative mechanisms of the Apollo digital innovation ecosystem, this research integrates global autonomous driving technology with the digital innovation ecosystem in a modular analysis. The innovative contribution of this paper lies in the construction of a collaborative mechanism for the Apollo digital innovation ecosystem from a modular viewpoint.