Green hydrogen technology encompasses the full chain of processes involved in producing, storing, and utilizing hydrogen from renewable sources. At its core is water electrolysis, with key technologies including alkaline electrolyzers (mature, cost-effective, suitable for large-scale industrial use with lower water purity requirements), PEM electrolyzers (high efficiency, over 80%, fast response, ideal for coupling with solar/wind), and AEM electrolyzers (emerging, combining cost advantages of alkaline systems with PEM efficiency, using non-precious metal catalysts). Storage technologies are equally critical: metal hydride systems, which store hydrogen by reacting with metals like magnesium or titanium, offer high density and safety for small-scale, mobile use (e.g., residential or on-vehicle storage). High-pressure gaseous tanks (35MPa, 70MPa) and cryogenic liquid tanks facilitate transportation and on-site storage. Utilization technologies focus on fuel cells, such as PEM fuel cells (efficient, quick-starting, dominant in transportation) and alkaline fuel cells, which convert hydrogen and oxygen into electricity with only water as a byproduct. These integrated technologies enable green hydrogen to be a viable, scalable clean energy solution.