Abstract: According to the practical problem of air leakage in the cover of Xingshan Iron Mine which was a mine translated from open-pit to underground mining, based on the theory of fluid flow in the porous media, the air leakage characteristics of the cover under the conditions of different porosity were simulated by FLUENT.The relationship between cover thickness and air leakage coefficient under the condition of different porosity was obtained.It is of great significance to instruct the cover formation of open-pit to underground mining.

Key words: Numerical Simulation, Air Leakage Characteristic, Cover, Porosity