Abstract: In view of the serious surface air leakage, goaf coal spontaneous combustion and carbon monoxide concentration overrun affecting safety production in shallow fully mechanized caving face, field measurement and theoretical analysis were combined to study the variation law of carbon monoxide concentration and its main sources in shallow fully mechanized caving face under surface air leakage condition based on the production technology of 6104 fully-mechanized caving face in Chuancaogedan Coal Mine. The results show that the concentration of carbon monoxide at the corner of 6104 working face is positively correlated with the concentration of carbon monoxide in goaf and the strength of surface air leakage. Carbon monoxide occurs in coal seam and floor of 6104 working face, and it enters into working face through mining cracks, which is one of the sources of working face carbon monoxide. Based on the production practice of the working face, the prevention technology to control the over-limit of carbon monoxide concentration in working face is proposed.