Abstract: The equipment and model test rig were designed for the chemical ignition of underground coal gasifi-cation (UCG) in a deep coal seam after analyzing the coal seam condition and coal quality which were suitable for UCG ignition. When the volmne ratio of silane to oxygen in the igniting composition keeps 1:3.33 and the pressure of the igniting composition maintains 0.3 MPa, the temperature rise rate in the ignition zone reaches 600℃·h^-1 the maximum temperature rises to 800℃, which can achieve UGC ignition in a deep coal seam. The temperature field of the coal seam was simulated on computer by the numerical simulation software FEMLAB. When the temperature in the ignition zone of the coal seam sets to 1366℃, the growth rate of the temperature field is 28.75℃·min^-1, which is consistent with the temperature change trend in model experiment.