With the development of information technology and digitization, the scale and complexity of scientific data are increasing. How to reasonably manage and utilize scientific data has become an important issue faced by governments and scientific research institutions. Based on the policy diffusion theory, the policy document measurement method and policy network analysis method were used to conduct a quantitative analysis of 46 national and 197 provincial scientific data policies from 2005 to 2022 in six dimensions, including time, space, intensity, breadth, speed and direction, to explore the diffusion of China's scientific data policies. Policy inspiration are put forward, such as optimizing the top-level design of policies and giving play to the role of national government administrative instructions, and streamlining administration and delegating power to lower levels, and making our policies more targeted in areas and regions, and expanding the mode of policy diffusion and strengthening the exchange of policy information among various parties.