In order to avoid the accident of CO poisoning in coal mines，according to the principle of adsorption catalysis，CuCl-CeO₂，a composite CO scavenger with both adsorption and catalytic properties，was prepared by thermal dispersion method using rare earth oxide CeO₂ as catalyst carrier and CuCl as adsorbent. The CO elimination performance of CuCl，CeO₂ and CuCl-CeO₂ was studied by cone calorimeter. At the same time，the peak pressure of gas explosion and the CO elimination effect of CuCl-CeO₂ were studied by a 20 L explosion ball-gas chromatography system. The results show that the CuCl-CeO₂ composite scavenger can effectively reduce the release rate of CO during the whole heating process，and its elimination performance is better than that of CuCl or CeO₂ alone. When the mass fraction of CuCl is 50 %，the CO elimination rate of CuCl-CeO₂ is the highest，reaching 88.0 %. With the increase of CuCl-CeO₂ mass concentration，the peak pressure of gas explosion gradually decreases，the time to reach the peak pressure of explosion is significantly delayed，and the amount of CO released is also decreasing. When the mass concentration of CuCl-CeO₂ is 1.00 g/L，the effect of explosion suppression and CO elimination is the best. The peak pressure of gas explosion is reduced from 0.508 MPa to 0.387 MPa，the time to reach the peak pressure of explosion is delayed from 237.6 ms to 483.2 ms，and the volume fraction of CO is reduced from 0.879 7% to 0.108 9%，which effectively reduces the peak pressure of gas explosion and CO release.