Abstract: According to the characteristics of low concentration gas in Dingji Coal Mine, such as many gas sources, large flow and long transportation distance, in order to realize the utilization of gas sources after even mixing, and to transfer the mixed gas to the thermal storage oxidation generator set safely, the gas mixing and transportation system of Dingji Coal Mine is designed from the aspects of process flow, pipe diameter selection, safety assurance, concentration mixing, etc. The field application shows that the system pipeline design and control parameters are reasonable, the gas transmission protection measures are perfect, the operation is stable and reliable, and the mixing concentration meets the requirements of thermal storage oxidation generator set.