Abstract: Due to the geological characteristics of inclined coal seams and the complex conditions of semi-coal rock roadways, gob-side entry driving faces challenges such as asymmetric large deformation of surrounding rocks and difficulties in roadway support.To reduce deformation of the roof, floor, and sidewalls in semi-coal rock roadways of inclined coal seams, a coal pillar width estimation model for gob-side entry driving in inclined coal seams was proposed based on the limit equilibrium theory, taking the 2401 return air roadway of Dengmaotong Coal Industry as an example.The plastic zone and stress distribution characteristics of the surrounding rocks were analyzed, and numerical simulations were used to compare the deformation and failure of roadways under different coal pillar widths.Based on this, a reasonable range for the coal pillar width was determined.Combined with field tests, the rationality of the coal pillar width was verified.The results show that the theoretical reasonable range for the coal pillar width is 4.68～5.46 m.Within this range, the expansion of the plastic zone in the surrounding rocks is limited, stress concentration is low, and displacement is minimal.The research findings can provide a reference for roadway excavation and support design under similar conditions.