Abstract: In order to study mechanical characteristics of coal and rock mass in coal seam excavation of normal fault, through establishing the mechanical model of coal and rock mass excavation in the vicinity of the normal fault, using FLAC^3D numerical calculation, we theoretically analyzed the coal and rock mass mechanical properties during excavation of upper and lower plates. The results show that horizontal displacement and horizontal stress have little effect on the excavation of the top rock mass of the coal seam. The vertical displacement caused by the ground stress and the considerable stress at the excavation top are the main factors causing collapse of the roof and the top of the excavated rock mass. When there is a normal fault, the considerable stress and vertical displacement caused by excavation from the upper plate is smaller than that caused by excavation from the lower plate. The closer the excavation area is to the fault, the greater the corresponding stress and vertical displacement at the top of excavation is. Under the same conditions, it is safer to excavate from the upper plate than from the lower plate. Therefore, in the actual project, the excavation of the coal seam from the lower plate should be avoided as far as possible so as to reduce the potential safety hazards.