Abstract: To compare the inhibitory effects of HFC-23 (CF₃H) and CO₂ on methane explosion characteristics, a 20 L spherical explosion pressure testing system was used to measure the effects of two inhibitors on the explosion limit range of CH₄ in air. The effects of two inhibitors with different volume fractions on the explosion pressure parameters of 9.5% volume fraction CH₄ were studied, and the explosion suppression triangles of the two inhibitors for CH₄ explosion in air were analyzed. The results indicate that both CF₃H and CO₂ can reduce the explosion limit range of methane in air, and the required volume fractions of CF₃H and CO₂ to suppress CH₄ detonation are 12.5% and 21.5%, respectively. Compared the explosion suppression parameters (peak reaction pressure and pressure rise rate) that inhibit CH₄ by volume fraction CH₄, the explosion suppression ability of 10% CF₃H is 1.95 times and 1.3 times that of an equal amount of 9.5% CO₂, but CF₃H with volume fraction of 4% has a weak promotion effect on the explosion of CH₄ when it used alone. The explosion suppression triangle of the two inhibitors shows that the explosive area under CF₃H suppression is smaller than CO₂, and the suffocation ratio of CF₃H in the safe area is 57% of CO₂.