Nowadays, geopolitical, extreme weather and other emergencies have exacerbated the global energy crisis, and thus, have increased the urgency of the world’s transition to sustainable energy. Sustainable energy policies play an important role in the process of sustainable energy transformation. The research on sustainable energy policy is mainly carried out through conventional qualitative and quantitative methods, in which bibliometrics and meta-analysis methods are paid attention to; however, the mining and analysis of the semantics of the relationships between policies are ignored. This paper uses knowledge graph technology to build a knowledge graph of China’s sustainable energy policy by using 10,815 open official documents of sustainable energy policy issued by China from 1981 to 2022. It forms the relevant policy archive storage and details related organizations. The legal source can be traced through the graph database, where the powerful synergy can be seen, and the policy focus can be monitored. In terms of structural data, this paper uses graph algorithms to identify key policy nodes at different stages, to identify the key government departments for policy issuance and cluster policy issuance departments, and it investigates China’s policy evolution in the issue of sustainable energy policies, the evolution of policy issuance departments, and the power co-evolution process between policy issuance departments. The research found that: (1) China’s sustainable energy policy was initiated in environmental protection, and the relevant policies on collecting pollution charges has continued to play an important policy node. Additionally, the three versions of the Environmental Protection Law of the People’s Republic of China have successively become the main legal source of other sustainable energy transformation policies. (2) The prominent feature of China’s sustainable energy policy transformation has involved transforming the process where the issuance of policies came from a single department to the joint issuance of documents by multiple departments. The joint exercise of government functions and powers by multiple departments jointly promotes sustainable energy policies’ implementation and play. (3) In the future, when formulating sustainable energy policies, the Chinese government should focus on the strategic and systematic aspects of the policies, so that the sustainable energy policies can meet both short-term and long-term development goals. At the same time, the synergy of various policies and measures should be fully played in implementing sustainable energy policies. The establishment of the policy knowledge graph based on publicly-open official documents can facilitate the analysis and visualization of sustainable energy policies, providing new ideas for policy research. This paper introduces the knowledge graph, graph machine learning algorithms and big data technology, which can deepen the depth and breadth of people’s research on sustainable energy policy. This study will help the public policy formulation work in the future and has a positive reference value for the evaluation of the implementation effect of policy objectives.
