In December 2018, the Central Economic Conference defined 5G, AI, industrial Internet and Internet of Things as “new infrastructure construction”, and subsequently included “strengthening the construction of a new generation of information infrastructure” in the 2019 Government Work Report. Network infrastructure construction, as the core of new infrastructure construction, can reduce the spatial barriers of information transmission, promote information exchange and knowledge spillover, and play an important role in realizing trans-regional cooperation and information exchange. In this context, the economic consequences of network infrastructure construction have become the focus of current academic attention. Existing literature has discussed the important role of network infrastructure construction in macroeconomic growth and the important impact on the production and operation of micro enterprises, but there is little discussion on whether and how network infrastructure construction affects the information disclosure behavior of enterprises. Based on this, from the perspective of accounting conservatism, this paper investigates the impact of network infrastructure construction on enterprise information disclosure. Specifically, this paper divides the samples into processing group and control group according to whether the registration place of listed companies is selected as the “Broadband China” demonstration city, and uses the DID method to systematically investigate whether and through what mechanism the network infrastructure affects the accounting robustness of local enterprises. The empirical results show that network infrastructure construction has a significant role in improving the accounting conservatism of enterprises. The mechanism test proves that network infrastructure construction enhances the accounting conservatism of enterprises by improving their information transparency. Further research shows that when the quality of external supervision and internal control is higher, network infrastructure construction has a more significant improvement on the accounting robustness of enterprises. The contributions of this paper are as follows: First, by studying the impact of network infrastructure construction on the accounting conservatism of enterprises, this paper expands the research on the impact of network infrastructure construction on micro enterprises from the field of production and operation to the field of corporate governance. Second, this paper enriches relevant literature on the impact of the strategic public infrastructure of China’s current economic and social development and the improvement of information transmission brought by broadband network construction on the accounting conservatism of enterprises. Third, different from previous literature on the impact of policies and approaches to promote information transmission on accounting conservatism, this paper verifies that network infrastructure construction can enhance information transparency and then enhance accounting conservatism through cross-space information transmission. Fourth, this paper provides empirical evidence on the impact of China’s network infrastructure construction on accounting conservatism, which can be a positive reference for investors, managers and policymakers.