Abstract: Foam gel fire-retardant material combines the anti-fire-extinguishing properties of two kinds of materials, gel and foam.It has the advantages such as strong stability, large diffusion range and high temperature resistance. In order to further determine the characteristics of the foam gel, the three-dimensional network structure of the foam gel was analyzed according to the geometric topology theory, and the foam gel was composed of gel particles and aqueous foam. In addition, the half-life of foamed gel exceeds 24 hours, which is more than six times that of the foam. It is proposed that the "strong-node and weak-rod" structure formed by gel particles is the key reason enhancing the stability of foamed gel. The inhibitory effect of the foam gel was investigated by using a resistivity test system to test the amount of CO released.The results show that the inhibition rate of foamed gel is 73.72%, higher than CaCl2 which is 57.35 %at 100 ℃,indicating that the foam gel has better resistance to coal spontaneous combustion. The field application shows that the foam gel can effectively prevent spontaneous combustion of coal.