Abstract: In view of the problem that the coal pillar of roadway protection in thick coal seam of fully mechanized top coal caving face is too large, resulting in the waste of coal resources, this paper takes the 6102 working face of Chuancaogedan Coal Mine as the engineering background, combined with the methods of theoretical analysis, numerical simulation and field test, and to analyze the stress of coal pillar of roadway protection with different widths and the distribution law of elastic-plastic zone.The results show that during roadway excavation, with the increase of roadway coal pillar width, the stress distribution on the goaf side of working face 6103 basically does not change significantly, while the stress distribution on the side of auxiliary transportation roadway of working face 6102 show a downward trend, and the stress superposition phenomenon in the middle of roadway coal pillar also show a downward trend.When the width of the roadway coal pillar is greater than 15 m, the plastic zone on both sides of the roadway coal pillar basically does not change significantly, and the width of the elastic zone in the roadway coal pillar increases with the increase of the width of the roadway coal pillar.During mining, when the width of the reserved roadway pillar is greater than 14 m, there is an elastic zone in the roadway coal pillar near the mining face.Considering comprehensively, the reasonable roadway coal pillar width is 14 m.Field practice has proved that the surrounding rock of the roadway has been well controlled.