To study the influence of different stope spans on the stability of stope in deep fracture areas,a structural surface investigation was carried out in a deep roadway of a mine,and the GSI classification of rock mass was carried out based on the results of the investigation.Then Hoek-Brown empirical strength reduction based on the GSI index was carried out to calculate the rock mass parameters and applied to the numerical simulation calculation.The impact of different mining spans on the stability of rock mass was studied by simulating the mining conditions under 4 working conditions of 3 m,4 m,5 m and 6 m respectively through Flac3D software.According to the simulation results and the field construction,it is recommended that the stope span be 3-4 m.