Abstract: According to the borehole hydraulic flushing trials conducted in Xieqiao Mine and Pansan Mine in Huainan Mining Area, the numerical simulation softwar e ANSYS was applied to the simulation resolution of the cavity formed before and after the borehole hydraulic flushing measures conducted.The variation conditions of t he coal stress, strain and displacement around the cavity before and after the flushing conducted were quantitatively analyzed.In the site reality, the analysis was condu cted on the outburst prevention mechanism of the borehole hydraulic flushing measures. The results showed that after the borehole hydraulic flushing measures conduct ed in the mineable low permeability outburst seam in a deep mine with no protective layer, the gas content after the borehole flushing conducted was improved about 5 0% higher than before the borehole flushing conducted, the gas drainage concentration and the drained gas pure flow were also improved about 3 times, the gas draina ge rate of the seam was highly improved, the coal elastic potential, the gas potential and outburst potential were reduced and the outburst danger of the seam was redu ced.