Abstract: The random model of heterogeneous porous foams was established based on the microscopic structure of porous foams. A random parameter-pore uniformity-was proposed to express the random distribution of pore diameters. The flow of air in heterogeneous porous foams was simulated by Ansys finite element software, and the formula for permeability of heterogeneous porous foams was created to study the random pore-diameter influence on permeability of heterogeneous porous foams. Results show that the simulation results from the established model were coincided with the experimental results from existing literature well. Both porosity and pore uniformity would affect the permeation rate of heterogeneous porous foams, the permeation rate increased with the increase of porosity and the decrease of pore uniformity.