In order to solve the problem of excessive gas concentration in the upper corner of the working face of Wan'an Mine, it was found that the gas technology of large-diameter drilling and high-flow extraction goaf can be applied by consulting relevant data, and reasonable calculation was determined by numerical simulation. Drilling arrangement spacing, field application and later observations showed that the gas concentration in the hole of large diameter drilling was 2.2% ~ 3.8%, and the gas concentration in the upper corner was maintained at 0.3% ~ 0.8%, which achieved good application results.