In order to overcome the difficulties in accurate monitoring of strands damage in the anchor clamp region of messenger wires in electrified railway,a new ultrasonic-guided wave transducer for damage monitoring is developed.In the investigation,first,a guided-wave guiding pin for the single wire of messenger wires is designed according to the specific structure of strands and the ultrasonic-guided wave propagation rule in Cu-Mg alloy messenger wires.Next,an independent elastic guided-wave emission-receiving unit is established with the guided-wave guiding pin at the core.Then,in consideration of outer layer structure of the messenger wire,an annular guidedwave detection module,which contains 12 emission-receiving units,is developed,and a new ultrasonic-guided wave transducer is formed by integrating an independent crystal control circuit with a covering /protecting handle.After that,a monitoring method for single-wire structural damage of messenger wires combined with the pulse echo detection and the specific wavelet de-noising is demonstrated.Finally,a series of detection experiments on singlewire artificial structural damage of 19-filament Cu-Mg alloy messenger wires are carried out.The results indicate that,when the distance between two transducers is 0. 1m and when the distance between the receiving transducer and the anchor clamp center is 0. 4 m,there is a positive correlation between the amplitude of wavelet-denoised damage echo and the damage depth,with an average relative error of 3. 16% and a length recognition error of 0. 025m ( less than the length of anchor clamp,namely 0. 055m) ,which means that the new transducer and the corresponding monitoring method help successfully achieve an ideal recognition of outer single-wire structural damage of an anchor clamp covering messenger wire.This research provides an effectivejudgement for the strengthening and replacing of damaged messenger wires in electrified railway.