Abstract: Deployable structures are structural systems capable of achieving large-scale configuration transformations between folded and deployed states. By enabling the reconfiguration of geometric forms and material distributions, such systems can satisfy complex engineering requirements including rapid deployment, high packing efficiency, and multifunctional integration. Targeting frontier applications in advanced construction, aerospace engineering, and space technologies, this paper systematically summarizes the research progress achieved by the authors’ team in the theoretical development, system innovation, and engineering applications of deployable structures. A unified stiffness analysis theory integrating structural mechanics and mechanism theory is proposed, together with an integrated analytical framework incorporating mobility determination, order analysis, and motion bifurcation identification. For rigid deployable structures, deployable scissor mechanisms and multi-morphology structural systems are developed with antennas and retractable roofs as representative application scenarios. In addition, geometric design and optimization methods for plate- and shell-based origami structures, as well as realization techniques for thick-panel configurations, are established. For flexible deployable structures, a topological library of membrane winding and folding patterns featuring both high packaging ratios and low damage characteristics is constructed, accompanied by thickness-effect correction strategies. Mechanical modeling methods considering the influences of wrinkles, creases, and seams are further developed, together with a dynamic analysis framework covering the entire deployment and folding process. With respect to elastic deployable structures, the dominant roles of crease design and stiffness distribution in governing motion trajectories and reachable configurations are clarified. On this basis, analytical and design methodologies are proposed for instability regulation, stable-state design, and shape control. The related studies have supported the development of proof-of-concept prototypes and engineering explorations for morphing wings, deployable antennas, retractable roofs, membrane shading systems, flexible solar arrays, and soft robots. Finally, in response to the growing demands for intelligence and multiphysics coupling, the key challenges and potential application scenarios of intelligent deployable structures are discussed. The presented work is expected to provide theoretical references and technical support for the continuous innovation and large-scale application of deployable structural systems in the field of civil engineering and related interdisciplinary domains.