In this article, the rationales of the hydrogen production in underground coal gasification are explained. The experimental conditions and process of the underground gasification in the Liuzhuang Mine, Tangshan, Hebei Province are introduced, and the experimental results are analyzed. By adopting the new method of two-stage underground coal gasification with long channels and big sections, the daily water gas production reaches about 22,950 m(3), with the maximum output of 53,550 m(3), in which H-2 content is between 41 and 74%, with both CO and CH4 contents over 7%. The daily average output of H-2 is 13,192 m(3). Experimental results show that the two-stage underground gasification with multi-point air (steam) feed cannot only improve the average temperature of the gasifier effectively, but also shorten the cyclical time for the two stages by a wide margin, which makes the time longer by 0.96-1.18 times and 1.27-1.91 times, respectively, when water gas with a high content of H-2 is produced, as opposed to that of a traditional mode of pumping air (seam) with fixed points for field and model tests.