Abstract: The porous aerostatic bearing is a core component of ultra-precision machine tools. Its static characteristics are significantly affected by the coupled influence of multiple parameters such as supply pressure, porous material thickness, permeability, and air film gap. Existing research has predominantly focused on open-type thrust bearings, with insufficient theoretical modeling of pressure distribution and analysis of multi-parameter synergistic effects for closed-type thrust bearings. Furthermore, in terms of parameter optimization, the accuracy and globality of optimization for radial bearings and thrust bearings are often limited by simulation data scale and computational efficiency. To address these issues, theoretical models is established for the static characteristics of both radial bearings and closed-type thrust bearings based on Darcy's law and the Reynolds equation. Using Matlab, the coupling effects of various parameters on load capacity and static stiffness are systematically revealed. The research indicates that load capacity and static stiffness change nonlinearly with the air film gap, exhibiting a clear optimal interval. Supply pressure, porous material thickness, and permeability significantly influence performance, with evident interaction effects among parameters. Furthermore, a genetic algorithm is employed for the automatic optimization of key parameters including supply pressure, porous material thickness, and permeability. Under the constraint of a load capacity not less than 500 N, a design maximizing static stiffness for different air film gaps (5-30 μm) is achieved. The optimized static stiffness can reach up to 1 306.3 N/μm. This method effectively enhances the adaptability and engineering practicability of bearing design, providing a reliable theoretical basis and optimization pathway for the high-performance design and manufacturing of porous aerostatic bearings.