瓦斯爆炸是煤矿生产重大灾害之一，爆炸过程具有突发性、链锁性等复杂特点，防控难度很大。本文通过对目前研究和采用的各类抑爆材料的抑爆效能进行对比分析，表明NH4H2PO4粉体对瓦斯爆炸有很好的抑爆效果。为了进一步分析NH4H2PO4粉体对瓦斯的抑爆作用，本文通过实验测试和量子化学分析软件对NH4H2PO4粉体热分解产物NH3和P2O5在瓦斯爆炸过程中的作用进行了研究。 采用GB/T12474-2008气体爆炸实验装置和20L近球型密闭式爆炸装置实验测试了NH4H2PO4热分解产物NH3和P2O5对CH4爆炸极限、火焰传播过程及爆炸压力特性的影响，结果表明：（1）NH3的存在使得CH4爆炸上下限均降低，爆炸极限范围缩短，CH4发生爆炸的容易程度增大；（2）NH3和P2O5对CH4爆炸过程均有抑制作用，且NH3在NH4H2PO4粉体热分解产物NH3和P2O5对瓦斯抑爆作用中贡献最大；（3）NH3浓度越大，对CH4爆炸过程的抑制作用越明显，且NH3对高浓度CH4抑制效果更显著。 采用Gaussian 09量子化学软件进一步分析了NH3在瓦斯爆炸过程的抑制作用，结果表明：氨气、氨基比甲烷、甲基更容易消耗爆炸过程中自由基羟基和氢基以及体系中的氧气，形成一个抑制甲烷爆炸的自促进-微循环反应，大大减少了甲烷爆炸链引发反应中甲基和链分支反应中甲醛的数量，从而延缓甲烷链锁反应进程，甚至中断爆炸链锁反应。

Gas explosion is one of the major disasters in coal mine production, the process of explosion has some abruptness and continuity, therefore, it is very difficult to prevent and control the explosion. The paper contrasted and analyzed the effects of various explosion suppression materials for studying and adopting at present, and found that NH4H2PO4 powder has obvious inhibitory effect on coal mine gas explosion. In order to further analysis the inhibitory effect of NH4H2PO4 powder on gas explosion, the author studied the effects of thermal decomposition products NH3 and P2O5 of NH4H2PO4 in the process of gas explosion through experiment and quantum chemistry software. With the help of GB/T12474-2008 gas explosion experimental device and near–spherical 20L explosibility test chamber, this paper firstly tested the changes of methane explosion limit, flame propagation process and explosion pressure after adding the thermal decomposition products NH3 and P2O5 of NH4H2PO4 , the results show that: (1) After adding NH3, the upper and lower explosion limits of CH4 decreased, the range of explosion limits reduced, the risk of explosion improved. (2) NH3 and P2O5 have inhibitory effects on gas explosion, but NH3 has bigger inhibitory contribution than P2O5 in the effect of NH4H2PO4 powder thermal decomposition products on gas explosion suppression. (3) the greater amount of NH3 was added, the better inhibition effect was represented for gas explosion; and it has a obvious inhibitory effect of NH3 on high concentrations gas explosion. The paper further analyzed the inhibitory effect of NH3 on gas explosion by Gaussian 09 quantum chemistry software, found that ammonia and amino are easier than methane and methyl on consumption of free radicals hydro and hydroxyl and oxygen, and formed a self promote microcirculation reaction in methane explosion suppression, it greatly reduced the number of methyl in the methane explosion chain methane, formaldehyde in branch chain reaction, thus reducing the process of methane chain reaction, even interrupt the explosion chain reaction.