In this paper,a CO concentration detection system with both ozone preparation and calibration performance is built based on the chemiluminescence method,low light detection technology and plasma discharge technology.The CO chemiluminescence pattern is also quantitatively explored by means of experimental methods,aiming to further reveal the mechanism of CO + O3 chemiluminescence reaction.The results show thatwhen CO is mixed with 1345 ppm ozoneat room temperature,CO mainly undergoes chemical excitation behavior with O atoms rather than ozone molecules to produce excited molecules.Due to the short lifetime of O atoms,there is a strong linear relationship between CO concentration and chemiluminescence intensity with R2> 0.99 when CO concentration is low.And the nonlinear effect becomes stronger when the CO concentration is high,and the rate of change of the detectedlight intensity becomes larger with the increase of CO concentration.