It is crucial to build an ecologically suitable regional innovation ecosystem against the imbalanced spatial pattern and uncoordinated development of regional innovation in China.#br#Gathering global innovation elements to construct an efficient self-organizing evolution innovation ecosystem has become an important way for regional innovation development. In recent years, with the rapid development of the digital economy, the wide application of digital technology has accelerated the reconstruction of regional and global economic patterns. Regional digital transformation driven by new-generation information technology such as big data and cloud computing has created an innovation ecosystem in the new era of the digital economy. The success of digital transformation is the key to the vigorous development of the digital economy and an important support for the stable and coordinated development of regional innovation ecosystems. However, the development of regional innovation ecosystems and innovation activities still faces multi-dimensional challenges,such as data collection, technology integration, talent supply, research and development costs, and data security. The impact mechanism of digital transformation on regional innovation ecosystem niche fitness is not clear, and it is of practical significance to explore the interaction between them. Meanwhile, industrial convergence has become a new trend of modern industrial development in digital transformation; as an important driving force for the growth of traditional industries and a new economic growth point, it plays a key role in promoting the formation and evolution of regional innovation ecosystems. In this process, the institutional environment plays an important role in ensuring and supporting regional innovation.#br#Drawing on the panel data of 30 provinces (autonomous regions, municipalities directly under the Central Government) in China, excluding Hong Kong, Macao, Taiwan,and Tibet, from 2008 to 2021, this paper empirically analyzes the impact of digital transformation on regional innovation ecosystem niche fitness and brings industrial convergence and institutional environment into the research model as mediating variables and moderating variables to analyze the interaction mechanism between them. The results show that, first of all, digital transformation has a significant positive impact on regional innovation ecosystem niche fitness; that is, the greater the degree of regional digital transformation, the more conducive to regional innovation, which is conducive to the development of the regional innovation ecosystem ecological niche in a more appropriate direction. Among them, the impact of digital transformation in the eastern region on regional innovation ecosystem niche fitness is significantly greater than that in the central and western regions. This is because the development level of the digital economy in the eastern region is relatively high, and thus it can better play the role of digital transformation in optimizing the regional innovation ecosystem's niche fitness. Secondly, industrial convergence plays a mediating role between digital transformation and regional innovation ecosystem niche fitness. Digital transformation can promote regional industrial convergence, and industrial convergence is conducive to the improvement of regional innovation ecosystem niche fitness. Finally, the institutional environment has a significant positive moderating effect on the relationship between digital transformation and regional innovation ecosystem ecological niche suitability. A good institutional environment can ensure the smooth promotion of digital transformation, which is more conducive to the enhancement of regional innovation ecosystem niche fitness through digital transformation.#br#Compared with existing studies, this paper empirically analyzes the relationship between digital transformation and regional innovation ecosystem niche fitness, and makes up for the lack of quantitative analysis in this field. Secondly, industrial convergence and institutional environment are included in the research framework of the relationship between digital transformation and regional innovation ecosystem niche fitness, and the mediating effect and regulatory effect of industrial convergence and institutional environment in this impact process are discussed, which enriches the existing theoretical research framework. Combined with the research conclusions, this paper puts forward policy suggestions on how to strengthen the digital transformation to enable the stable development of regional innovation ecosystem, providing reference for the coordinated innovation and high-quality development of different regions in China.#br#