The rock is a geological media that underwent distortion and destroy. The failure of rock is progressive failure process that is conduced by the inner flaws under the condition of the outside load. This process has intimate relation with the media’s inner flaws. The pilot study on the failure law of brittle rock with prefab crack is carried out by numerical sisulation
and the influencing mechanism of the cracks on the brittle rock failure is analyzed. Based on the study results
some conclusions can be drawn. In the failure process of the brittle rock with prefab crack under load
the existence of the cracks becomes the master factor that influences the failure mode of the brittle rock instead of the heterogeneity. And the distance between the prefab cracks is an important factor influencing the failure mode of the brittle rock with double cracks.