With the continuous growth and accumulation of public data resources, evaluating the economic value of public data openness has become an important issue. It is of great significance for optimizing data resource allocation and facilitating data circulation. Based on this, this paper adopts the registration information of all newly established firms in China from 2009 to 2019 to construct new firm entry data at the city-industry level, and takes the launch of public data open platforms as a quasi-natural experiment to empirically test the impact of public data openness on new firm entry using the DID method. The study finds that public data openness significantly promotes new firm entry. Mechanism testing indicates that reducing entrepreneurs’ information search costs and improving government transparency are the two main channels through which public data openness promotes new firm entry. Further analysis reveals that the promotion effect of public data openness on new firm entry is mainly observed in non-state-owned enterprises, service industries (especially living services), and cities with higher Internet penetration rates. Additionally, the higher the quality of public data openness, the stronger the promotion effect on new firm entry. New firm entry is an important source of economic growth and job creation, and the promotion effect of public data openness on new firm entry fully validates the resource allocation effect of public data. The rapid development and widespread application of digital technology have led to the emergence of the digital economy. Data is the foundation of digitization, networking, and intelligence, and a key production factor in the development of the digital economy. Although existing literature has thoroughly explored the entrepreneurial effect of digital economic development, there is currently no direct evidence or systematic analysis on how data as a production factor itself affects new firm entry. This paper investigates the effect of public data openness on new firm entry from the perspective of data as a production factor, effectively supplementing the theoretical analysis and empirical research on the economic value of data as a production factor.