In the process of coal seam mining, it is easy to cause problems such as large roof overhang area and long collapse step, which affects the failure form of the surrounding rock of the roadway and the deterioration and failure of the supporting body. In view of the occurrence of thick and hard roofs in the 113105 working face of the Bojiang Haizi Mine and the instability of the narrow coal pillars along the empty roadway, the use of roof cutting and pressure relief is an effective way to effectively solve the problem of roof overhang, and the design of its key parameters has an important impact on the pressure relief effect. In order to explore the influence of different roof cutting pressure relief heights on the roof stress evolution law above the narrow coal pillar along the empty roadway, the effect of lateral roof cutting of roadway was studied by combining theoretical analysis, numerical simulation and field observation. Based on the slip-revolve stability theory of masonry beams, the mechanical model of the roof of the coal pillar under different roof cutting heights was constructed, and the bearing stress distribution equation of the coal pillar after different roof cutting heights was obtained. FLAC3D software was used to simulate the stress distribution and displacement evolution characteristics of the coal pillar roof under different roof cutting heights. The simulation results show that the slitting surface formed after the implementation of roof cutting technology effectively blocks the stress propagation path, and the vertical stress peak value in the coal body on both sides of the roadway decreases, and the pressure relief effect gradually increases with the increase of the roof cutting height, when the roof cutting height reaches 19 m, the stress of the coal pillar roof decreases by 17.22 MPa, and the pressure relief rate is 43.4%. The displacement of the roof of the coal pillar gradually decreases with the increase of the roof cutting height, and the reduction rate gradually decreases. The field test shows that according to the designed roof cutting height, the stress of the surrounding rock is significantly reduced, and the deformation degree of the roadway meets the normal mining requirements.