The unavoidable increase in train speed and load, as well as the aging of railway facilities, is requiring more and more attention to rail defects detection. As a promising tool for rail, in-service high-speed inspection, guided wave–based detection technologies have been developed in succession by researches in the past two decades. However, there is a lack of a systematic review on the developments and performances of these technologies. This article reviews ultrasonic rail inspection methods comprehensively with the focus on the state-of-the-art technologies based on guided wave. Different excitation options, including train wheel, electromagnetic acoustic transducer, pulsed laser, air-coupled, and contact piezoelectric transducer, are described, respectively, along with their inspection sensitivities, regions, and potential speeds. Finally, future challenges and prospects are discussed to a certain extent to provide references for researchers in this area.

列车速度和负荷不可避免的增加，以及铁路设施的老化，要求越来越多地关注铁路缺陷检测。作为一种很有前途的铁路在役高速检测工具，基于导波的检测技术在过去二十年的研究中相继发展起来。然而，缺乏对这些技术的发展和性能的系统评价。本文重点介绍了基于导波的最新技术，全面回顾了超声波钢轨检测方法。分别描述了不同的激励选项，包括火车轮、电磁声换能器、脉冲激光、空气耦合和接触压电换能器，以及它们的检测灵敏度、区域和潜在速度。最后，