煤与瓦斯突出是一个能量释放的过程，瓦斯膨胀能是由煤层游离瓦斯与解吸瓦斯膨胀做功产生的能量，是煤与瓦斯突出的主要能量来源。发生煤与瓦斯突出时，煤层内部瓦斯在降压环境下进行解吸，为探讨逐级降压解吸下瓦斯膨胀能的变化特性，以晋城矿区无烟煤为研究对象，利用瓦斯吸附-解吸试验装置，进行逐级降压解吸和常压解吸2种解吸试验，分析了逐级降压解吸下解吸瓦斯膨胀能变化特性。研究结果表明：吸附平衡压力越大，煤中吸附瓦斯内能越大，体系稳定性越差，在外界扰动下易于发生煤与瓦斯突出事故；吸附平衡压力相同时，常压环境下解吸瓦斯膨胀能高于降压解吸下解吸瓦斯膨胀能，且随着吸附平衡压力升高，二者的差值逐渐增大，2.5 MPa吸附平衡压力时常压环境下解吸瓦斯膨胀能比降压环境下解吸瓦斯膨胀能高28.6%；降压环境下环境压力对解吸瓦斯膨胀能起到一定程度的抑制作用，且环境气体压力越高，抑制效果越明显；降低解吸瓦斯膨胀能可作为一种防治煤与瓦斯突出技术途径。

Coal and gas outburst is a process of energy release. Gas expansion energy is the energy produced by the expansion of free gas and desorbed gas in the coal seam. It is the main source of energy for coal and gas outburst. When coal and gas outburst occurs, the gas inside the coal seam is desorbed under a reduced pressure environment. In order to explore the change characteristics of gas expansion energy under stepwise pressure reduction and desorption, the anthracite coal in the Jincheng Mining Area is used as the research object and the gas adsorption-desorption experimental device is used. Two desorption experiments of stepwise decompression and desorption and atmospheric desorption were carried out, and the change characteristics of desorption gas expansion energy under stepwise decompression and desorption were analyzed. The research results show that the greater the adsorption equilibrium pressure, the greater the internal energy of the adsorbed gas in the coal, and the worse the stability of the system. Coal and gas outburst accidents are prone to occur under external disturbances; when the adsorption equilibrium pressure is the same, the desorption gas will expand under normal pressure. The energy is higher than the desorption gas expansion energy under reduced pressure desorption, and as the adsorption equilibrium pressure increases, the difference between the two gradually increases. Under 2.5 MPa adsorption equilibrium pressure, the desorption gas expansion energy under normal pressure environment is higher than that under reduced pressure environment. The gas expansion energy is 28.6% higher; the ambient pressure in a reduced pressure environment can inhibit the desorption gas expansion to a certain extent, and the higher the ambient gas pressure, the more obvious the suppression effect; reducing the desorption gas expansion energy can be used as a way to prevent coal and gas technical means of gas highlighting.