The effects of bromotrifluoromethane (CF3Br) as a representative of halogenated extinguishing agents on CO removal through catalytic combustion over Cu-Ce bimetallic oxides (CuCeOx) were investigated at low temperatures. Gaseous CF3Br can decrease CO conversion to threaten the stability of CuCeOx, especially under the higher CF3Br concentration and weight hourly space velocity. The potential interactions between CF3Br and CuCeOx and the subsequent formation of a few halides on the catalyst surface are responsible for the variations in the CO oxidation performance of CuCeOx. Moreover, the mechanism of CF3Br interference on CO catalytic oxidation over CuCeOx catalyst was proposed. The presence of CF3Br might slow the reaction of adsorbed CO (carbonyls) on Cu sites with surface active oxygen and compete with gaseous O2 for adsorption on oxygen vacancies of the ceria support to cover Ce sites by resulting deposition of inactive species. Significantly, the complete deactivation of CuCeOx catalyst by CF3Br is difficult because of the stronger and more effective interaction between CuCeOx catalyst and CO rather than CF3Br at low temperatures.