Foam ceramics as a porous medium have demonstrated huge utilization potentiality to suppress multiple and continuous gas explosions in coal mines. Explosion suppression ability and thermal conductivity of different foam ceramics was analyzed. Explosion energy that combines propagating velocity and overpressure was introduced to evaluate suppressing effect. It was indicated that the overpressure was significantly attenuated by foam ceramics. Besides, for two types of foam ceramics, Al2O3 foam ceramic showed a better suppressing performance on explosion energy than SiC. Foam ceramic of bigger pores exhibited a better inhibition effect on explosion energy. It was found that, as foam ceramic become thicker, thickness was becoming the dominant influential factor suppressing gas explosion. The results suggest foam ceramics with larger pores present a higher thermal conductivity, which account for why larger pores foam ceramic exhibits a better suppressing ability. It is a wall effect that prevents chemical chain reactions, the heat of flame would be transferred to the skeleton, and free radicals are reduced.