In the process of underground coal mining, sometimes the original roadway section size cannot meet the normal production and needs to be expanded. Aiming at the problems of reducing the stability of roadway surrounding rock, expanding construction technology and supporting design, taking the occurrenc

e of belt conveyor roadway and the existing supporting conditions in the north wing panel of 5-2 coal seam in Huixing Coal Mine as the background, the safety and stability of surrounding rock and the limit span of roof are studied by combining theoretical analysis with numerical simulation, and the feasibility of expanding the side and increasing the span of belt conveyor roadway in the north wing panel is demonstrated. The stress evolution law of surrounding rock, the development characteristics of plastic zone and the safety and stability of roadway coal pillar before and after expansion are compared and analyzed. Combined with the limit self-stable equilibrium arch theory of roadway support, it is concluded that the failure depth of the two sides before and after the expansion of the belt conveyor roadway in the north wing panel is basically unchanged, and the roof failure height and the limit equilibrium arch height after the expansion are increased by 13.1% and 10.9% respectively. On this basis, the support parameters of the expansion section are determined, and the expansion construction technology of 'reinforcing the anchor cable in the roof before the expansion, supporting the new excavation roof and the expansion side in time during the expansion ' is proposed. Finally, the expansion construction and support field application research were carried out. The results show that there is no obvious crack in the surrounding rock of the expansion section, and there is no obvious spalling and moving deformation on the surface of the surrounding rock, and the overall safety and stability of the roadway.