Ceramic matrix composites (CMCs), as a novel class of integrated structural and functional materials, exhibit both metallic toughness and ceramic hardness. Thanks to their properties of high strength, heat resistance, chemical stability, and creep resistance, CMCs have emerged as the preferred choice for critical thermal structural components in aerospace, energy, and other sectors. Their performance is heavily reliant on textile preforms, which not only dictate the mechanical properties of the materials but also directly influence their thermal shock resistance and crack propagation resistance. Currently, there remains a gap in systematic research on preform structure design, hindering theoretical breakthroughs and the engineering applications of CMCs. In response to this scenario, this section systematically reviews the structural forms and inherent characteristics of typical preform structures, including 2D/3D woven, braided, needle-punched, and stitched preforms. The aim is to provide designers with fundamental concepts and design guidelines, enabling customized preform development and fostering the advanced application of CMCs in high-end fields.