Abstract: For the problems that 7521 material roadway in a mine extruded by goaf hanging arch, through theoretical analysis, numerical simulation,deformation monitoring, we analyze the influence of different length hanging arch on roadway deformation, the role of directional hydraulic fracturing technology in cutting hanging arch and compared deformation of crack area and non-crack area. The results show that the longer the length of the hanging arch, the greater deformation on roadway; the directional hydraulic fracturing achieves the goal of cutting roof hanging by changing periodic weighting distance; the deformation of roadway has reduced by 40% or so.