In this paper a porous media seepage model was applied to analyze the permeability and study the seepage process of crystal pillar formed in the preparation of electronic grade phosphoric acid (EGPA). By inspecting the seeping process, the structure parameter of crystal pillar could be obtained. Two basic ideal models (perfectly separated model and perfectly connected model) were presented and a characterized factor ？ was introduced to modify the model. A good simulation result was obtained which met the experiment result well. The relationship between ？ and permeability were also discussed. The characterized factor ？ showed potential application on optimizing process.
