Abstract: In order to better understand the cracks producing laws of coal seam in grouting fracturing under different confining pressure, we establish a two-dimensional model of stress and strain through RFPA-flow software to simulate fractures initiation, propagation until the model instability of the whole injection process of coal seam in different confining pressure. The results show that in the grouting fracturing process of coal seam, changing confining pressure directly affects the initial fracture pressure and buckling pressure of the coal, and there is a positive correlation between them; with the increase of confining pressure, grouting stress is concentrated around the hole and crack generation becomes more difficult; the slurry flow will also become difficult, and grouting effect is ineffective.