A semi-confined chamber was designed and an explosion suppression experiment on the effect of different spraying volume of methane-oxidizing bacteria and ultra-fine water mist on methane-air premixed mixture was studied. The methane-oxidative bacteria morphology

flame change visualization in the explosion suppression process

maximum explosion overpressure and the average pressure rise rate are analyzed. The results show that the ultra fine water mist containing methane-oxidizing bacteria-inorganic salt can effectively degrade methane

the larger the spray amount is

the faster the methane degradation speed is. With the methane volume being 9.5% and the flame propagation rate being 0.7 ml

when the methane had degraded after 360 min

the flame brightness and the flame propagation rate were lower than the situation caused by methane that had not degraded. When the spraying volume was added from 0.7 ml to 4.9 ml

the maximum explosion overpressure in the chamber decreased and the average pressure over the close part of the chamber decreased. The results indicate the synergistic effect of methane oxidizing bacteria-inorganic salt and ultrafine water mist on methane explosion. It can effectively degrade the methane in certain period of time.