Abstract: The return airway of 8204 working face in a mine uses the layout way of small coal pillar protecting roadway. In order to analyze small coal pillar damage degree and coal seam permeability, based on ABAQUS numerical simulation, from the study of mining disturbance caused by fracture zone space structure, overlying strata stress field distribution characteristics, the paper analyzes small coal pillar stress state, damage strain and temporal and spatial distribution of permeability during tunneling and mining period. The simulation results show that the coal pillar permeability coefficient near tunneling working face rapidly increases; permeability coefficient rapidly decreases as the coal pillar is forward or backward away from the tunneling working surface; the coal pillar failure behind working face is serious, and comparing with the tunneling period, the permeability of coal pillar coefficient increases greatly, and the local increase is more than two orders of magnitude.