Abstract:The 3102 return airway is protected by 6m coal pillar, and the 3-1 coal seam mined in the adjacent 3101 working face is spontaneous combustion coal seam. Due to the influence of lateral pressure in goaf and tunneling, the deformation of coal pillar in the 3102 return airway is large. In order to ensure the safety of roadway driving and avoid spontaneous combustion of residual coal in adjacent goaf, the evolution law of fissures in coal pillar is analyzed through simulation analysis and field observation. The results show that with the gradual expansion of the fissures in the coal pillar in the 3102 return airway, and there are through-fissures in the coal pillar, the fissures in the coal pillar can be divided into four areas. The research results provide reference for adopting targeted fissures blocking technology in mines.