Abstract:     The rapid integration of digital technology and traditional industries has profoundly changed the production and operation modes of the economy and society, stimulated new scenarios and new tracks of innovation activities, and brought new momentum to improve the quality of regional innovation and help innovation-driven development. Based on the connotation of digital economy and innovation quality, an index evaluation system of the digital economy and innovation quality was constructed, and 271 cities at the prefecture level and above in China were taken as research samples to study and analyze the impact of digital economy on the innovation quality and its temporal and spatial characteristics. The results showed that: (1) digital economy can significantly improve regional innovation quality. By dividing innovation quality into innovation potential quality, innovation spillover quality and innovation output quality, it is found that digital economy has the largest positive promoting effect on innovation spillover quality and the least positive promoting effect on innovation potential quality; (2) the impact of digital economy on innovation quality has a significant marginal increasing effect, that is, the higher the level of digital economy, the stronger the positive promoting effect on innovation quality, the digital economy has the lowest threshold value for innovation spillover quality and the highest threshold value for innovation output quality; and (3) digital economy has a significant spatial spillover effect on the improvement of regional innovation quality, and the spatial spillover effect on innovation spillover quality is the strongest and most significant, while the spatial spillover effect on innovation potential quality and innovation output quality is not significant. The research conclusions are helpful to further understand the deep action process of digital economy on regional innovation quality, and they have provided objective evidence and policy basis for regional efficient use of digital economy to enable innovation quality improvement.

Key words: digital economy, innovation quality, spatial-temporal characteristics