Abstract: In order to research the coal stress distribution laws after hydraulic flushing, based on the hydraulic flushing field test condition, we use RFPA^2D-Flow software to simulate the process of coal fracture after hydraulic flushing, and analyze the effect of the amount of coal from hydraulic flushing boreholes on seam stress distribution. The result indicates that hydraulic flushing pressure relief and permeability is a process that the coal around punching holes relieves pressure and stress concentration transfers to deep of coal. With the increase of the amount of coal from hydraulic flushing, the phenomenon of stress concentration is more obvious and the distance from flushing hole is more further, in consideration of coal stress distribution in hydraulic flushing coal seam, the amount of coal from hydraulic flushing should be from 0.4 t/m to 0.8 t/m.