The porous air bearing materials enable the gas throttling effect through internal pore structures. The simulation modeling of the pore structure is the prerequisite for researching the gas flow state and the bearing air film stiffness parameters. Aiming to solve the distortion problems of a single pore structure and simplified boundary conditions in the current porous material modeling process, a filling model generated via random spherical particles was proposed. Based on the normal distribution of particle diameter as well as the random position distribution, the model was used to simulate the real pore structure of porous restrictor. Along with the composite modeling DIGIMAT software, the 3D model with micro-hardness simulation was generated using ABAQUS software. The feasibility of the random filling modeling method was verified by comparing the simulation results with those obtained through hardness experiments. Hence, a reference for the modeling of high-density porous materials was provided for studying the lubricating medium flow state and material cutting mechanism in porous materials.