Abstract: The injection rate of gasification agent is an important factor affecting the yield of gasification products and gas calorific value in the process of underground coal development. In order to reveal the effects of residence time and heating rate on the gasification behavior and product distribution characteristics of lignite in Santanghu Basin, the gasification and pyrolysis experiments of Xishanyao Formation lignite in Santanghu Basin under different residence time and heating rate were carried out based on a fixed bed gasifier. The results show that（1）with the increase of residence time, the conversion rate of semi-coke and gas yield increase, and the water yield increases first and then decreases. Under high temperature conditions, the secondary reaction is aggravated, and the methane conversion reaction is promoted, resulting in a significant increase in the volume of H2, but the total mass of pollutants is reduced.（2）With the increase of heating rate, the semi-coke conversion and gas yield decreased, and the yield of water and tar decreased first and then increased. Under high temperature conditions, the secondary reaction is inhibited, the volume of H2 is reduced and the total mass of pollutants is increased.（3）It is suggested that in the actual production process, by controlling the moving speed of steam injection to increase the residence time and reduce the heating rate, the generation of H2 can be significantly increased, so as to improve the efficient and clean development of underground coal gasification process. The research results can provide theoretical guidance for the underground coal gasification process of lignite in Xishanyao Formation of Santanghu Basin.