CH4-CO2-O2 reforming to syngas in a novel Ba0.5Sr0.5Co0.8Fe0.2O3-d oxygen-permeable membrane reactor using LiLaNiO/g -Al2O3 as catalyst was successfully reported. Excellent reaction performance was achieved with around 92% methane conversion efficiency, 95% CO2 conversion rate, and nearly 8.5mL/min.cm2 oxygen permeation flux. In contrast to the oxygen permeation model with the presence of large concentration of CO2 (under such condition the oxygen permeation flux deteriorates with time), the oxygen permeation flux is really stable under the CH4-CO2-O2 reforming condition.