<p>The global wave of digital transformation has fueled the rapid growth of public data, which is becoming an essential driver of enterprise innovation and technological catch-up. While prior research has shown that public data openness (PDO) can promote firm innovation, its potential to narrow the technology gap (TG) in emerging economies remains unclear. This paper exploits the staggered rollout of PDO platforms across Chinese cities as a quasi-natural experiment and combines it with panel data of publicly listed manufacturing firms from 2012 to 2022. The results show that PDO significantly narrows the TG between Chinese manufacturing firms and the global technological frontier. Mechanism analysis reveals that this effect operates through intensified market competition, enhanced inter-firm collaboration, and reduced innovation costs. Heterogeneity analysis indicates that the effect is more pronounced for firms in technology-intensive industries, in cities with stronger governance capacity, and in regions with better intellectual property protection. Moreover, although external technological restrictions—such as those imposed by the United States—tend to widen the TG, PDO appears to offset some of their negative impact. By focusing on the allocation of digital production factors, this study contributes to the literature on PDO and technological catch-up and provides novel policy insights for promoting high-quality manufacturing development in emerging economies.</p>