“A hydrothermal method was used to prepare α - Fe2O3/rGO composite material, and a catalytic luminescence (CTL) sensor for detecting carbon monoxide (CO) was constructed. The sensor consists of a ceramic heating rod coated with sensitive materials, a quartz reaction chamber, a gas flow path, an injection system, a photomultiplier tube, and a signal processing unit, which can achieve real-time acquisition of the luminescence signal generated during the CO catalytic reaction process. The crystal structure and morphology of the prepared material were characterized using X-ray diffraction, nitrogen adsorption desorption, and transmission electron microscopy, and the detection conditions were systematically optimized. The results indicate that the α - Fe2O3/rGO composite material has a higher CTL response compared to α - Fe2O3. The linear range of CO detection by this sensor is 80~1125 mg/m3, with a detection limit (S/N=3) of 26 mg/m3, and no significant response to common interfering gases. The recovery rate of CO in simulated mixed gas samples is between 104% and 110%. Mechanism research infers that CO is oxidized by O - on the surface of α - Fe2O3/rGO to generate excited state CO2, which radiates luminescence upon returning to the ground state. The constructed CTL sensor based on α - Fe2O3/rGO composite material can achieve rapid and highly selective detection of CO, providing new technical support for online monitoring and emergency warning of CO, and offering new ideas for the design of CTL gas sensitive materials.”