Abstract: According to coal spontaneous combustion accidents occurred in No. 42- 43 steeply inclined ultra thick seam goaf in Chenxingyuan Mine,the analysis on ro ck strata movement law showed that roof side crack air leakage affected by mining activities and great left coal complex role would be main factor affected to coal spontan eous combustion in goaf. According to the serious air leakage at surface ground of fire area and the wide distribution and three dimensional distribution features of falling d own coal area,fire comprehensive control technology of fire zone with backfill to seal air leakage, borehole construction of underground mine borehole drilling and casing int egration rapid fire distinguishing was provided. The application of those technologies could effectively control firing zone to be extended and could successfully extinguish f iring zone.