The energy industry serves as the core driving force of the global economy, with a vast and complex industrial chain that encompasses the entire process from resource development and energy conversion to end-use applications. Driven by climate change, energy security, and technological innovation, traditional fossil fuels and emerging renewable energy sources are increasingly intertwined, gradually reshaping the global energy landscape. In this context, the energy industry chain is not merely an extension of supply chain management but also a critical nexus connecting policy, finance, technology, and markets. A comprehensive understanding of its upstream and downstream structure, as well as its development trends, has become essential for evaluating energy transition and industrial competitiveness.