Abstract: To reveal the inhibition characteristic of foamed gel used for coal spontaneous combustion, the test system for coal spontaneous combustion index gases was established to compare and analyze the heating rate and the development law of index gases of coal treated by different foam inhibitors, and the synchronous thermal analyzer was used to analyze the characteristic temperature and pyrolysis characteristic of coal. The results show that the critical temperature T_rl, the slow oxidation temperature T_ml and the burnout temperature T_me of coal treated by different foam inhibitors are higher than that of raw coal. For the coal sample treated by foamed gel, the initial exothermic temperature increased from 29.77 °C to 89.61 °C, and the maximum heat release power reduced from 50.15 mW/mg to 37.11 mW/mg. The inhibition rate of coal samples treated by water, foamed mud and foamed gel were 2.54%, 5.28%, and 10.1% respectively. The heating rate and velocity of producing CO and C₂H₄ of the coal sample treated by foamed gel are always slower than that of foamed mud and water. So the inhibition characteristic of foamed gel is better than that of water and foamed mud.