Abstract: In order to study the reaction between the pyrolysis zone and the gasification zone in the pressurized fixed bed gasificationprocess,the pyrolysis and semi-coke gasification process of the fixed bed hydrogen-rich atmosphere was simulated,and the influence ofpressure,heating temperature and hydrogen-rich ratio on coal pyrolysis were investigated by the pressurized hydrogen-rich pyrolysis de-vice. The mechanism of the influence of various factors on pyrolysis was analyzed. The pyrolysis of semi-coke in hydrogen-rich atmospherewas used as raw material. The experimental study was carried out by pressurized thermogravimetric analyzer. The change of carbon conver-sion rate and CO_2 reaction rate with time under different temperature and different pyrolysis raw materials and the effect of hydrogen-richratio on gasification reaction activity were analyzed. The results show that in the atmospheric pressure hydrogen-rich atmosphere pyrolysistest,with the proportion of hydrogen rich increasing,a large amount of H are provided and the concentration of H is increased. During the pyrolysis process,the free radicals will continuously combine with H to form stable components. Including a large number of small mole-cules of volatiles and some tar precipitation,the volatiles in the semi-coke decrease by 0.69%,the semi-coke yield decreases by 4.8%.The semi-coke yield under the pressurized conditions is higher. The semi-coke yield with the increase of pressureis not obvious law. Thevolatile matter gradually decreases,but the change is small. With the increasing of the final temperature,the volatile yield gradually increa-ses in the hydrogen-rich atmosphere. H in hydrogen rich atmospherewill combine with free radicals to form a small molecular structure andescape,and the semi-coke yield and volatile matter will gradually decrease. Increasing the proportion of hydrogen richcan increase the ma-turity of the semi-coke,the proportion of hydrogen rich increases from 0 to 35%,and the concentration of H increases. Small molecules canbe rapidly hydrogenated to form volatiles,while the macromolecules will also hydrogenate into a stable structure,the semi-coke volatilesdecreases by 1.46%,the semi-coke yield decreases by 2.50%. Hydrogen-rich pyrolysis can significantly promote CO and CH_4 productionat 35% H_2,reaching 91.2 mL/g and 63.8 mL/g. From the experimental study of gasification characteristics,it can be known that increas-ing the gasification reaction temperature can improve the gasification reaction activity of hydrogen-rich semi-coke and CO_2. The gasifica-tion activity of pyrolysis char in hydrogen rich atmosphere is similar to that in inert atmosphere,which shows that hydrogenation pyrolys-iscan improve tar yield,tar quality and gas quality,and has little effect on the gasification activity of semi-coke.