Abstract: In order to determine reasonable width of segment coal pillar of 2301 fully mechanized working face with large mining height in Jiaoping Mining Area, taking coal pillar stress monitoring as entry point, lateral abutment pressure distribution is analyzed; elastic zone width and coal pillar roadway width of plastic zone is obtained through theoretical calculation. On this basis, the width of segment coal pillar is determined. Finally, the deformation and fracture of coal pillars with different widths is simulated by FLAC^3D. The reasonable width of coal pillar at large mining height working face is 25 m. Field application shows that coal pillar width scheme satisfies the requirements of roadway protection for adjacent working face.