Abstract: This paper simplifies the percolation model into a physical model of the n-stage pipeline presence of sand seepage segment, and establishes the basic equations of fluid flow in porous media.By establishing the seepage partial differential equations, combining with Darcy‘s law, Kozeny-Carman equation, and then using Fourier transform method to solve these partial differential equations, we derive the expression equation of seepage rate K.We then determine the expression of the pipeline segment sand seepage parameters and mathematical model of pressure in the pipeline.Finally, by analyzing obtained pressure distribution, the mathematical model of the pipeline pressure distribution is established