Abstract: In order to explore the reasonable width of cave-along roadway in inclined coal seam and analyze the stability mechanism of coal pillar, the numerical models of cave-along roadway with different widths of coal pillar were simulated and analyzed based on FLAC3D. The results show that the failure modes of roadway surrounding rock and coal pillar are different with different width of coal pillar. In the gently inclined coal seam, the deformation distribution of the surrounding rock along the gob and the gob generally shows a change trend of the large middle and small two sides of the gob, and presents asymmetric deformation characteristics. As the width of the coal pillar increases, the stress distribution of the coal pillar shows a transition trend from tensile stress to compressive stress. When the width of the coal pillar is ≥7 m, the plastic shear zone on both sides of the gob near the coal pillar is separated from the surrounding rock on the top of the gob and transferred to the gob, and the stress distribution within the coal pillar shows the characteristics of principal compressive stress. When the width of the coal pillar is about 7 m, the deformation in the middle span near the gob is the largest, but the safety of the narrow coal pillar in the roadway excavation along the gob is high, which can effectively avoid the excessive bearing of the coal pillar, induce the vertical pressure to the solid coal side of the roadway, and achieve the purpose of reducing the tensile failure of the roadway roof and peeling the shear failure zone of the gob along the gob.