Abstract: The desorption characteristics of coal seam gas have a significant impact on the gas outburst patterns in mines and the development of coalbed methane. With the changes in the temperature and pressure of the coal seam, there is a clear control effect on the desorption of soft and hard stratified coal gas.To further enhance the understanding of coal gas desorption characteristics within Guizhou province, this research focused on the soft and hard coal layers in Xiaotun and Qinglong coal mines of the typical Qianxi mining area. Using the High-precision Coal Analyzer (HCA), experiments were conducted to study the gas desorption characteristics under various temperatures and pressures. A comparative analysis was performed to evaluate the impact of coupled changes in temperature and pressure on the gas desorption characteristics of these coal layers. The findings indicate that for the same coal sample, higher temperatures and pressures accelerate the initial rate of gas desorption. Within the initial 120 seconds of desorption, gas pressure does not play a dominant role. The initial desorption rate in soft coal layers is higher than in hard coal layers, but the total volume of gas desorbed is greater in hard coal layers. Notably, hard coal layers can surpass soft coal layers in cumulative gas desorption within 540 seconds. The most dramatic changes in coal gas desorption occurred within the first 60 seconds after coal exposure, with soft coal layers showing a higher proportion of desorption in this period, thus being more "active". The desorption rate increases with pressure and can be divided into three phases: the "desorption explosion phase" (0-60 seconds), the "desorption jump phase" (60-1500 seconds), and the "desorption stabilization phase" (1500-7200 seconds). The median desorption time in coal layers is inversely related to temperature and pressure, with soft coal layers being more sensitive to these factors than hard coal layers, particularly within the first 1800 seconds post-exposure. These results provide a foundation for further studies on gas emission patterns in soft and hard coal layers in other mining areas, development of coalbed methane, and the enhancement of gas control technologies in Guizhou coal mines.