Abstract: At present，from a view of a micro perspective, an analytical study based on a real coal sample,were not conducted on the issue of the gas seepage law. With a method of seepage simulation applied to establish a model, a CT scanning was applied to establish a gas fat coal model of normal porous structure. With the application of the Avizo Software to select a part of software, a simulation analysis was conducted on low pressure gas seepage with the inlet and outlet pressure difference of 0.74 MPa. The study results showed that along the length of the gas seepage and the has pressure was steadily decreased. The max seepage velocity was occurred near the outlet of the pore well developed, at the area with the porous diameter reduced suddenly, the seepage velocity also would be suddenly increased. In the completed seepage process, due to the bending and detour of the pores in coal seam, the gas would be accumulated in coal seam internal, a part of the gas would be delayed in the non-connected pores, the variation of the mass flow would be existed in a certain fluctuation, the gas quality and flow at the outlet would be less than the gas flow at the outlet.