Abstract: In order to solve the problem of unreasonable coal pillar width in Qitaihexintie Coal Mine, based on the study of regional distribution characteristics of su rrounding rock deformation and failure, the numerical simulation analysis was used to study the surrounding rock deformation law and reasonable coal pillar width of ste ep seam. The results showed that the lower area working end face was heavily affected by surrounding rock movement, and the influence scope was 30. 5 m, stress pe ak was 23. 12 MPa. The different coal pillar width had great influence to roadway support, the engineering practice showed that roadway with 15 m width pillar was reas onable and feasible, maximum roof convergence was 87 mm, maximum floor heave was 231 mm and the rib deformation was 52 mm. The 15 m width pillar could effecti vely contral the deformation of roadway.