Hydrogen energy is the energy released by hydrogen during its physical and chemical transformations. Hydrogen is widely distributed on Earth, with a mass abundance of 0.14% in the Earth's crust (Hydrogen makes up about 75% of the mass of ordinary matter in the universe. The latest observation results show that ordinary matter composed of atoms such as hydrogen and helium only accounts for 4.9% of the universe's content, and dark matter accounts for about 26.8% of the universe, which is more than five times that of ordinary matter. The remaining 68.3% is “dark energy” which is neither matter nor light. On Earth, hydrogen has an atomic abundance of 15.4% and a mass abundance of 0.14% in the crust), ranking as the tenth most abundant element. Hydrogen primarily exists in a combined state within substances such as water and organic matter. Only a minimal amount of free hydrogen is found in the Earth's crust and atmosphere. The majority of hydrogen utilized by human society is produced from other energy sources, with feedstocks commonly derived from fossil fuels and water. Hence, it is considered a secondary energy. Hydrogen possesses multiple attributes, serving as industrial feedstock, low-carbon fuel, and energy storage medium. The hydrogen energy industry encompasses pivotal segments such as hydrogen production, storage, delivery, conversion, and use, as well as equipment manufacturing. It not only constitutes a vital component of the traditional industrial system but also marks a significant development direction of strategic emerging industries.