<p>Porous aerostatic bearings, which employ porous media for gas throttling, offer outstanding pressure equalization characteristics and are extensively utilized in high-precision measurement and machining systems. The performance of porous aerostatic bearings is intrinsically linked to the physical and mechanical properties of the porous materials used. Consequently, comprehensive theoretical investigation, precise design, meticulous fabrication, and rigorous testing are imperative for performance enhancement and evaluation. This review systematically examines the structural characteristics and functional applications of five prevalent configurations of porous aerostatic bearings: radial, thrust, spherical, localized, and tilting-pad types. It further consolidates current theoretical modeling approaches and solution methodologies, with a particular emphasis on the interplay between microstructural pore characteristics and their influence on overall bearing performance. The performance requirements for porous materials, including permeability, porosity, Young's modulus, and roughness, are discussed. The research progress on four main types of porous materials—metals, ceramics, graphite, and new materials—is compared, along with their design and preparation processes. Additionally, methods and devices for testing bearing performance, such as load capacity, stiffness, vibration, and slewing accuracy, are thoroughly reviewed. Finally, the review consolidates current advances and future directions, highlighting the essential role of micro–macro synergy in advancing porous aerostatic bearings technology. This review provides critical theoretical support and practical guidance for the design, optimization, and application of porous aerostatic bearings, contributing to the advancement of ultra-precision machinery and fluid dynamics technologies.</p>