It is estimated that the energy released by the sun every second can be used by all humans for about 700000 years. Simulating the sun to generate endless clean energy has become humanity's ultimate energy dream. Why is it difficult to achieve the dream of "artificial sun"? What is the current global and domestic R&D progress bar? In nature, nuclear fusion is not an unfamiliar phenomenon. The sun is like a huge thermonuclear fusion reaction device, undergoing fusion reactions at all times - hydrogen nuclei continuously collide and fuse into helium nuclei, releasing enormous energy and delivering it to Earth. However, the Earth does not have the high temperature and pressure environment that can sustain nuclear fusion like the Sun. The primary challenge in creating the 'sun' is to create the harsh environment required for fusion. In theory, deuterium tritium plasma needs to be heated to over 100 million degrees Celsius, about 6 to 7 times the temperature of the Sun's core, in order to overcome the Coulomb repulsion between atomic nuclei and undergo sustained fusion. Controllable nuclear fusion combines the challenges of plasma physics, nuclear engineering, materials science, and other fields, making it one of the most complex energy systems ever conceived by humans. Nowadays, global fusion energy research and development has entered a new stage of multi-path parallel and rapid iteration. The mainstream technological routes can be divided into two categories: magnetic confinement and inertial confinement. Among them, magnetic confinement stabilizes high-temperature plasma in a vacuum container through a strong magnetic field, achieving long-term continuous reactions. Tokamaks and star mimics are its main device types; Inertial confinement utilizes high-energy lasers or particle beams to compress and heat fuel pellets in a very short period of time, bringing them to fusion conditions. At present, several large tokamak experimental devices in the world have been able to achieve the harsh conditions required for fusion reactions in a short period of time. However, how to further improve fusion power gain, enhance plasma confinement performance and stability, maintain long-term combustion, and obtain net energy output still faces enormous scientific and engineering challenges. The International Thermonuclear Experimental Reactor (ITER) is currently the largest fusion research project in the world, carrying the beautiful aspiration of humanity for the peaceful use of fusion energy. It is jointly constructed by multiple countries and will be assembled in 2020. After successful completion, it will prove the feasibility of magnetic confinement fusion science and engineering technology, laying the foundation for demonstration power plants from 2040 to 2050. Recently, the 2nd Ministerial Conference of the World Fusion Energy Group and the 30th International Atomic Energy Agency Fusion Energy Conference were held in China. At this conference, the International Atomic Energy Agency Fusion Energy Research and Training Collaborative Center was established in Chengdu, marking a significant leap in China's international status and influence in the field of fusion energy. China is one of the few countries in the world with a complete nuclear industry system, and has formed an innovative system in the field of controllable nuclear fusion led by national major scientific and technological infrastructure and industry university research collaboration. For example, in 2025, "China Circulation III" achieved for the first time that the temperature of both the atomic nucleus and electrons exceeded 100 million degrees Celsius, marking significant progress in China's controllable nuclear fusion technology; The All Superconducting Tokamak Nuclear Fusion Experimental Device (EAST) has set a new world record in Hefei, Anhui, achieving "high-quality combustion" at 100 million degrees Celsius for 1000 seconds for the first time; The first key component of the compact fusion energy experimental device (BEST) host, the Dewar base, has been successfully installed, marking a new stage in the construction of the main project... Huang Mei, the technology leader of China National Nuclear Corporation, introduced that China National Nuclear Corporation is currently conducting research and development of fusion reactors according to the "experimental reactor demonstration reactor commercial reactor" model. It is expected that combustion plasma experiments will be conducted around 2027, and the construction of a pilot reactor will begin after the relevant technology matures. After demonstrating fusion energy output at this stage, commercial reactor construction will begin. In the future, once humanity successfully ignites the "torch" of controllable fusion, its impact will far exceed technological breakthroughs themselves, bringing about profound global and systematic changes. As the ultimate clean energy source that is theoretically inexhaustible, fusion energy will fundamentally break humanity's dependence on fossil fuels; At the same time, it will also drive the development of clusters in cutting-edge fields such as superconducting materials and artificial intelligence control. (New Society)