To explore the large-scale operation characteristics of regenerative flameless oxidation devices for ultra-low concentration coal mine methane, this study analyzed the influence of different types of porous media on the stable combustion range of flameless oxidation of ultra-low concentration methane based on a laboratory-scale platform, and revealed the mechanism of heat accumulator arrangement and inlet methane parameters on the temperature field distribution of the device. On this basis, a pilot-scale test device for ultra-low concentration methane with a treatment capacity of 800 Nm3·h-1 was developed. During field tests at the No. 8 Coal Mine of Pingdingshan Tian’an Coal Industry Co., Ltd., the influences of inlet parameters on the bed temperature distribution, methane oxidation efficiency, and emission characteristics of CO and NOx of the large-scale flameless oxidation device were obtained under different inlet methane volume concentrations and flow rates. It is found that the pore structure of porous heat accumulators has a significant effect on the regenerative oxidation process. Among them, the 20 PPI foam ceramic heat accumulator has the widest stable combustion range, and both the flashback and blow-off limits increase with the rise of inlet methane volume fraction. The honeycomb ceramic heat accumulator has a narrower stable combustion range but lower flow resistance and a lower flashback limit. The abrupt interface change formed by the arrangement of heat accumulators with different pore structures and the structure of the reaction chamber can construct a flame anchoring zone. A good combustion stability effect can be achieved when the chamber length-to-diameter ratio is 0.8, and the reaction temperature is generally positively correlated with the inlet methane volume fraction and flow velocity. The local reaction enhanced by the abrupt interface change and the thermal feedback from the downstream heat accumulator tend to homogenize the temperature distribution in the reaction chamber. Under the condition of 4%–7% field-extracted methane, the temperature of the reaction chamber of the oxidation device can be maintained at 650℃–1 100℃, and the high-temperature zone moves slightly upstream with the increase of inlet methane volume fraction and flow rate. Under the test conditions, the methane destruction rate of the oxidation device is not less than 96%, and the exhaust CO and NOx are both lower than the environmental limits. From the perspective of porous structure regulation and reaction chamber scale matching, this paper reveals the synergistic mechanism of expanding the stable combustion range and suppressing flashback risk, completes the engineering scale-up from laboratory scale to pilot scale, and provides a basis for the large-scale application of ultra-low concentration methane flameless oxidation devices.