After nearly 40 years of rapid development, the Chinese economy has entered a crucial period of transformation from old to new growth drivers. The Internet, as a new driving force for economic development, is bound to promote a new round of technological and industrial changes. In this context, it is of great theoretical value and practical significance to answer the question of whether and how network infrastructure can affect the information transfer and technological knowledge diffusion of micro-enterprises. This study uses “Broadband China” as a quasi-natural experiment and finds that the construction of network infrastructure can not only promote the diffusion of technological knowledge within companies, but also promote the diffusion of technical knowledge between companies. This article further finds that when the technology level of a listed company is high, the geographical locations of its subsidiaries are scattered, and the network infrastructure of subsidiaries is relatively complete, the network infrastructure has a greater positive effect on the diffusion of technological knowledge within the company. Similarly, network infrastructure has a greater influence on the diffusion of technological knowledge among companies because of the high technology level of listed companies and the large number of Internet users.

The research in this article has important academic value and practical significance: (1) Preliminary studies have shown that infrastructure has an important impact on company operations. Most of their studies focus on transportation infrastructure, and our research on network infrastructure is a further supplement to the literature on infrastructure. (2) With regard to the research of network infrastructure, academics now pay more attention to the influence of the macro level. Few scholars test how network infrastructure affects the diffusion of enterprise technological knowledge from the micro enterprise level, especially from the internal and external aspects of listed companies. (3) On the research of innovation, previous scholars find that the development of macro factors such as infrastructure has an important impact on the innovation activities of enterprises themselves. This paper takes other subjects associated with listed companies as the research object, studies the role of network infrastructure on the diffusion of technological knowledge, and expands the literature on innovation. (4) This paper uses “Broadband China” as an exogenous event to solve the causal inference problem between network infrastructure and economic growth. (5) The research of this paper is of great significance to the practice of public goods supply such as Internet.