Abstract: In order to study the air leakage law in the goaf of 110 construction method working face, the 110 method working face of a certain mine was taken as the research object.Based on the characteristics of the ventilation system of the 202 working face, SF6 tracer gas measurement technology was used to measure the air leakage rate and air leakage volume of the flow field in the goaf under Y-shaped ventilation conditions of the 110 method working face on site.The results indicate that there are multiple air leakage channels in the goaf of the 202 working face from the release point to the receiving point, with an average air leakage rate of 0.21～0.33 m/s.There is air leakage between the 202 goaf and the working face, as well as the return airway.There is also air leakage between the 201 goaf and the 202 auxiliary transportation lane, with an air leakage rate ranging from 77 to 92 m³/min.The overall air leakage law of the 202 goaf is obtained.