The invention discloses a combustible gas explosion parameter testing device. The device comprises an explosion cavity, a vacuumizing system, a gas supply system, a heating system, an ignition system, a data collection system and a tail gas treatment system. The explosion cavity is used for explosion reaction of combustible gas. The vacuumizing system is used for vacuumizing the explosion cavity. The gas supply system is used for adding the combustable gas into the explosion cavity. The heating system is used for heating the combustible gas in the explosion cavity. The ignition system is used for igniting the combustible gas in the explosion cavity. The data collection system is used for testing explosion pressure of the combustible gas in the explosion cavity. The tail gas treatment system is used for discharging and treatment of waste gas generated after the combustible gas explodes in the explosion cavity. The testing device can test explosion lower limit, maximum explosion pressure and explosion indexes of the combustible gas at high temperature and high pressure, and plays a guide role in taking prevention measures in enterprise fires and explosion accidents.