Prestressed concrete cylinder pipe (PCCP) is widely used in long-distance water conveyance and urban water supply systems. Under the combined effects of corrosion, prestress relaxation, cyclic loading, and manufacturing defects, prestressing wires may fracture, leading to local prestress loss, reduced load bearing capacity, and, in severe cases, catastrophic pipe bursts. To address the challenges posed by the concealed nature of wire breakage, the large spatial extent of PCCP pipelines, and the need for in-service monitoring without interrupting water delivery, this article first analyzes the causes and structural consequences of wire breakage and then systematically reviews the monitoring principles, system configurations, research progress, and engineering applications of acoustic methods, electromagnetic methods, and distributed acoustic sensing (DAS). Comparative analysis indicates that acoustic methods are well suited to capturing transient wire breakage events and providing online early warning, but their performance is susceptible to variations in propagation paths and environmental noise. Electromagnetic methods can provide relatively direct estimates of the number and spatial distribution of broken wires, but their accuracy depends strongly on equipment calibration and pipeline parameters, while conventional internal inspection is often constrained by shutdown and dewatering requirements. DAS offers distinct advantages in long-distance coverage, continuous monitoring, and distributed localization along the pipeline. In response to the insufficient discussion of technology integration trends and future scientific challenges in existing reviews, this article further summarizes the evolution of PCCP wire breakage monitoring from event identification toward condition assessment and risk prediction, and from single-modality sensing toward multisource fusion and coordinated monitoring. Future research should focus on establishing reliable relationships between wire breakage signals and residual load bearing capacity, as well as improving intelligent identification under complex noise conditions. A multisource fusion framework that integrates online detection using acoustic methods or DAS, electromagnetic verification, and assessment based on structural models should be developed to promote the transition of PCCP monitoring from event identification to condition assessment and risk prediction. This review provides a reference for the selection of PCCP wire breakage monitoring technologies, system design, and engineering applications.