Abstract:    In recent years, the digital economy has developed rapidly and it is becoming an important contributor to China′s national economy and a new driving force for its economic growth. At the same time, the digital economy can accelerate the flow of various innovative resources and factors. Due to the characteristics of digital technology, there have been various changes in product innovation, process innovation, organizational innovation, and business model innovation. The digital economy has gradually become a key factor affecting regional innovation capacity. Based on the existing research on the measurement framework of the digital economy, this paper clarified the connotation of the regional digital economy, defined the accounting scope and related industries of the regional digital economy. This paper systematically calculated the digital economy added value of 31 provincial-level regions in China from 2007 to 2020 from the four dimensions of digital empowerment infrastructure, digital media, digital transactions, and digital economic transaction products. Based on this, this paper empirically tested the driving role and impact law of the digital economy on regional innovation capacity by constructing a two-way fixed-effect model and a threshold model.The results of this study showed that the digital economy added value of various provincial-level regions in China has shown a trend of continuous increase and the growth rate has been accelerating. There are significant regional differences in the scale of digital economy development in China, with the scale of digital economy development in the eastern region significantly larger than that in the central and western regions. The industrial structure of the digital economy in China is not balanced. Although the proportion of added value from digital media and digital transactions in the total added value of the digital economy is continuously increasing, the added value of digital empowerment infrastructure is still the main contribution to the digital economy in various regions. The digital economy can significantly promote the improvement of regional innovation capacity. It has become an important driving factor for regional innovation, and to a certain extent, changes the influence law of innovation factors on innovation capacity. The digital economy has a significant nonlinear and differentiated impact on regional innovation capabilities, and there exist two thresholds for the scale of digital economic development. As the scale of the digital economy continues to grow, the promotion effect of the digital economy on regional innovation capacity shows a non-linear characteristic law of decreasing marginal effect and then increasing marginal effect.Finally, in order to further promote the rapid development of the digital economy and strengthen the empowering role of the digital economy on regional innovation capacity, this paper proposed corresponding countermeasures from three aspects: optimizing the industrial structure of the digital economy, implementing differentiated development strategies for regional digital economy, and improving the quality of investment in innovative manpower and capital.This paper has filled the gap and made up for the deficiencies in the measurement of the digital economy scale at the regional level in China′s existing research. This paper systematically calculated the development of the digital economy in 31 provincial-level regions in China in the past 14 years from the perspective of the added value of the digital economy industry. It can more intuitively examine the development scale of the digital economy in various regions and the changes in the status of the digital economy in the national economy. At the same time, this paper, for the first time, explored the driving role and influencing law of the digital economy on regional innovation capacity from the perspective of the development scale of the digital economy. This paper will enrich the research on relevant innovation theories and has practical significance for understanding the development of the regional digital economy in China and promoting high-quality development of the digital economy.

Key words: digital economy, development scale, regional innovation, threshold model