Abstract: In order to control the extremely complex +1 030 m horizontal fourth mining fire area with a wide spread concealed smoldering state at 4238 working face of Huashan Mine, combine active fire-fighting with partition isolation and fire control as the basic idea, comprehensive fire-fighting techniques, such as remote sealing after shrinkage, inorganic material filling, liquid carbon dioxide cooling, nitrogen injection inerting, flyash slurry filling in the roadway and filling in the surrounding roadway in smoldering fire areas, have been successively adopted for treatment. The results show that the fire in 4238 working face has been extinguished, after a long time of high intensity treatment, the fire has been gradually extinguished, the concentration of carbon monoxide gas is controlled below 1×10-5, at present, the management of the fire area is at the end stage.