An effective patent transaction market can enhance the efficiency of the innovation system, playing a critical role in new idea allocation and technology diffusion. However, frictions in the technology market hinder patent transactions. Therefore, this paper investigates whether the enhanced information accessibility resulting from broadband infrastructure can promote firm patent transactions by utilizing the staggered rollout of China’s Broadband China Strategy (BCS) across cities as an exogenous shock. Using newly constructed firm-level patent transaction data and the difference-in-differences (DID) approach, we find that BCS increases firm patent transactions by 7.6%. Our results still hold after a series of robustness checks. Our mechanism analysis indicates that the expansion of patent transaction networks and firm digital transformation are the channels through which broadband infrastructure promotes firm patent transactions. The heterogeneity analysis reveals that BCS has stronger impacts on patent transactions for high-tech and large firms, as well as for firms located in regions with better intellectual property rights protection.