Abstract:Deep-hole blasting mining is prone to rock slicing and over-exploitation, which leads to the increase of stope span and affects the stability of the stope. Based on modern simulation technology, numerical simulation of the ground pressure appearance of the stope under different spans is carried out, the distribution of stress, displacement and plastic zone of chamber roof under different mining span was compared and analyzed, discuss the internal relationship between different stope spans and lithology. Research shows: the horizontal displacement of the pillars of different spans does not change significantly, as the span increases, the tensile stress and settlement of the top plate increase, the increase in the stope span will lead to a gradual increase in the safety risk of the roof. The study of ground pressure behavior law under different mining span has certain guiding significance, which can provide reference for the optimization design in engineering practice.