Abstract: To address the issues of poor adhesion, water leakage, and difficult repairs associated with traditional waterproofing sheets, this paper reviews the types, performance, structural design, and construction applications of spray-applied waterproofing membranes in composite linings, and analyzes the current status and development trends of this technology. Firstly, the development history of spray-applied waterproofing membrane materials is summarized, comparing the waterproofing performance, durability, adhesion, and mechanical properties of different materials, while analyzing the influence of interfacial behavior and failure mechanisms on structural performance.Secondly, through numerical simulations and engineering case studies, the advantages of spray-applied waterproofing membrane linings in terms of load-bearing capacity and construction efficiency are verified, with key technical requirementsfor construction processes elaborated. Finally, the challengesin occupational health and safety,standardization, and adaptability to complex conditions are identified, suggesting future improvements through material optimization, development of environmentally friendly products, refinement of design theories, and standardization of construction techniques to promote wider application in tunnel waterproofing engineering.