Abstract: Aiming at the problem that a large amount of recoverable coal occurs under buildings of Pingmei Shares No.12 Coal Mine, and in order to achieve steady development, control surface subsidence and reduce gas management difficulty, the paper puts forward mining mode of using solid filling to fill goaf and mine the coal under the building. Through the filling process practice, the problems of filling material into the gob, related technologies and parameters are solved. In the case of ensuring the integrity of the buildings on the ground, it can effectively mine coal under buildings above 4 630 000 t in Pingmei Shares No.12 Coal Mine, which provides an effective process for the liberation of "under three" coal in Pingmei Shares.