Hydrogen is a key component of the future national energy system and an important carrier for achieving green low-carbon trans⁃formation in energy end-use sectors. The large-scale supply of green and low-cost hydrogen is an urgent need for the future developmentof the energy system. Underground coal gasification (UCG) technology efficiently can convert in-situ coal into hydrogen-rich combustiblegas, and store CO2 during gasification into gasification cavity, which is expected to be an ideal low-cost hydrogen supply path. The gener⁃ation mechanism of hydrogen-rich gas during UCG was focused on, typical engineering cases of hydrogen production via UCG was sum⁃mariztd and cost of different hydrogen production technologies and deepens the deep UCG coupled with carbon capture, utilization, andstorage (CCUS) hydrogen production pathway were compared. The research results indicate that, the direct sources of hydrogen-rich gasin the UCG process include coal pyrolysis reaction, steam-reducing reaction, and water-gas shift reaction in the gas flow channel at lowertemperature. The medium-to-low temperature pyrolysis zone in the coal seam is a significant part of the product gas, which mainly pro⁃duces hydrogen-rich gas H2 and CH4. The rich water characteristics of the coal seam and the high gasification activity of H2O (g) makethe reduction zone dominated by the steam decomposition reaction. Moreover, the long gas flow channel at lower temperature and catalyticeffect of gasification slag further promote water-gas shift reaction. Operating data from typical demonstration projects at home and abroadhave verified that UCG has a natural advantage in producing hydrogen-rich gas, and its hydrogen production cost is much lower than thatof surface coal gasification and natural gas. Injecting carbon dioxide back into the gasified cavity has the dual advantages of mineral car⁃bonation and physical carbon storage. Coupling CCUS technology with deep UCG for hydrogen production and simultaneously producingchemicals or jointly driving deep oil/ gas recovery can form a low-cost hydrogen production path with near-zero carbon emissions of carbondioxide. The coupling of CCUS technology with deep UCG for hydrogen production has important significance for exerting the pillar role ofa new energy system, solving the carbon emission problem of fossil energy hydrogen production, and it is a road to clean transformationand development of fossil energy with Chinese characteristics that conforms to the national conditions of China.