Abstract: This article is based on the mining of longwall working faces in thick coal seams with large inclination angles.Aiming at the issue of reasonable roadway protection coal pillar width in roadway excavation along goaf,a combination method of theoretical analysis and numerical simulation is adopted for carrying out research.Based on the limit equilibrium theory,a coal pillar mechanics model is established,and the calculation formula for the widths of plastic zones on both sides of the coal pillar is derived.The reasonable width of the coal pillar is preliminarily determined to be 7.93 m.Through FLAC^3D numerical simulation,the surrounding rock deformation and stress distribution characteristics under different coal pillar widths （6-14 m） and roadway widths （3-6 m） are analyzed.The results show that when the width of the roadway protection coal pillar is relatively small,the stress of the roadway surrounding rock is concentrated and the deformation is significant;As the width of the coal pillar increases,the surrounding rock deformation gradually decreases,and the subsidence of the roof and the deformation of the side walls are effectively controlled;When the width of the coal pillar is 8 m,it can ensure the stability of the surrounding rock while balancing economic benefits;As the width of the roadway increases,the roadway protection coal pillar stress concentration area first increases and then decreases,the deformation amount of the side walls and the subsidence amount of the roof also increase accordingly.The research results provide scientific bases for the design of reasonable coal pillar width of roadway excavation along goaf in large inclination angle coal seams.