Abstract: The integrated energy system with multi-energy integration and complementary utilization is the key to achieving energy transition goals. In recent years, the EU's planning and layout in this field have been particularly prominent. In recent years, the European Union's planning and layout in this field have been particularly prominent. In 2018, the EU developed a vision of the integrated energy system by 2050 and then proposed the R&D Roadmap 2020-2030 in 2020. This article analyzes the EU's integrated energy system R&D roadmap from the aspects of background, budget and key research areas, and summarizes the main components, building blocks and research priorities of the integrated energy system. Suggestions for the development of a clean, low-carbon, safe and efficient multi-energy integration system of China are proposed, including reinforcing the top design of the future multi-energy integration energy system; developing a short, medium and long-term R&D roadmap; establishing an efficient R&D and innovation organization system; developing flexible and autonomous regional energy communities centered on consumers; building highly flexible energy markets suitable for future energy systems; and deeply integrating digital technology with the integrated energy system.

Key words: European Union, Integrated Energy System, R&D Roadmap, Carbon Neutral