Abstract: Long flame coal from Daliuta Coal Mine was taken as the research object, X-ray three-dimensional microscope was used to scan the ore core of the coal sample, with the application of three dimensional reconstruction technology and image gray-level segmentation technology, coal microscopic pore model of coal sample was established. Based on the model,the finite element mesh model of coal sample was established. Fluent software is used to simulate the water seepage condition at micro pore model under different pressure in order to draw the laws about water seepage under different pressure. The results show that under the same pressure, along the direction of water seepage, coal pore pressure decreases; along the central pore and wall direction, water speed varies from large to small until to zero. Under different pressure conditions, with the increase of inlet pressure, pressure gradient increases gradually, the overall speed of water seepage also increases obviously, and its maximum value will tend to a steady value, the maximum average speed all appeared near the pressure inlet between 12 μm and 18 μm. Different pressure and channel conditions have obvious influence on the water seepage regular.