Abstract: In order to study explosion suppression characteristics of CO2 to mine multicomponent flammable gas,a FLACS software was ap-plied to numerical simulati on on explosion parameters of different concentration ratio mixed CH4,CO,C2H6,H2 mixed gas with CO2 addedand the influence law of CO2 to the explosion suppression characteristics of the multicomponent flammable gas was obtained. The resultsshowed that CO2 could have a suppression role to the explosion of flammable gas and expl osion suppression effect would be better with thevalue of CO2 added increased. With CO2 added increased,the parameters of combined gas explosion characteristics woul d be affected,espe-cially CH4. The parameters influences on the combined gas explosion characteristics of H2,C2H6,CO concentration mixed ratios individu-ally as 0. 1: 0.3 : 0.8 would be more obvious than the influence of pure CH4. Meanwhile,CO2 added could slow down variations of thepressure filed of above mixed ratio mixed gas,t emperature field,product concentration field,could delay time of explosion reaction andcould reduce the explosion danger.