Abstract: Abstract: The study on analysis of source of CO in the upper corner on the working face of Xichuan coal mine was carried out through field experiments and laboratory demonstration methods in terms of frequent occurrence of CO in the upper corner with concentration exceeding the standard requirements in the coal mining process of working surface of Xichuan coal mine, which determined that the main source of CO in the upper corner of 1113 working surface of Xihcuan coal mine is the low temperature oxidation of residual coal in goaf, followed by low-temperature oxidation of coal body on the working surface, and high-temperature oxidation of coal body of coal wall in the cutting process of coal mining machine and CO generated due to rupture of covalent bond of coal molecular. The release of CO of original occurrence in the coal seam can be eliminated.