Abstract: The digital economy is gradually becoming a new engine for high-quality economic development in China. Analyzing the impact of the digital economy on high-quality economic development based on its internal linkage and operating characteristic has important theoretical and practical significance. Based on the urban data of China from 2011 to 2021, this paper conducts an empirical research with a dual fixed-effect model. The findings show that the linkage between digital infrastructure, digital industrialization and industrial digitalization has injected strong impetus into the high-quality economic development. The construction of digital infrastructure can effectively help the high-quality economic development by supporting digital industrialization and industrial digitalization, and digital industrialization can provide new impetus for high-quality economic development by promoting the process of industrial digitalization. While the digital economy enables the high-quality economic development, there is a reverse spillover effect. The development of digital industrialization will lead to the accumulation of related digital resources and produce a siphon effect, and the accumulated resources will further promote the high-quality economic development. However, with the continuous deepening of digital industrialization, this effect will gradually weaken. The reverse spillover effect of digital industrialization will not only be affected by its own level of development, but also by multiple factors such as the regional economic development level, the unemployment rate and the marketization level.

Key words: digital economy, high-quality economic development, internal linkage, network operating characteristic