Abstract: Based on numerical simulation, analogy simulation and theoretical analysis, the effect of coal cutting height on the laws of recovery rate and mine pressure of fully-mechanized sublevel caving face is studied. The results show that increasing coal cutting height could increase ventilation section and shorten the coal caving time, which is helpful for improving the top coal recovery ratio. However, with the increasing of coal cutting height, roof activity height and influence scope of abutment pressure would increase; the phenomenon such as rib spalling and roof fall would appear in all higher probability; the working face would need higher-level of hydraulic support parameters and properties. Therefore, in order to keep the safety of special thick seam fully mechanized mining, coal cutting height can not be increased blindly. The reasonable coal cutting height should be determined according to the concrete conditions of coal seam occurrence.