Based on the self-built experimental set-up, the propagation law of explosion flame of hydrogen/methane premixed gas with different hydrogen volume fractions in different equivalent ratios was investigated under the action of a corrugated fire-retardant core. The experimental study shows that the flame isolation and suppression effect of the corrugated fire-retardant core at different equivalence ratios is either promoted or suppressed, the hydrogen/methane premixed gas ex¬plosion flame is quenched without hydrogen mixing when ϕ = 0.8 and 1.0, and also quenched when ϕ = 1.2 in different hydrogen volume fractions. The corrugated flame-retardant core significantly affected the extinguishing of the explosion flame of the premixed gas when ϕ = 1.2, the flame propagation speed and overpressure showed a similar trend under different volume fractions of hydrogen. When the flame is quenched, the flame is depressed inward to form a reverse spherical cell flame, reverse diffusion combustion phenomenon occurs, and it lasts a long time, eventually, the combustion reaction extinguished. The flame penetrated the corrugated fire-retardant core during the rest of conditions. When ϕ = 1.0, the flame reaction of the hydrogen/methane premixed gas explosion under the action of the corrugated fire-retardant core is the most violent, and its propagation speed and overpressure jump rapidly until it reaches a peak.