介绍安装在运营电力机车上的弓网状态检测系统的组成及工作原理。讨论了故障点地面坐标的几种确定方法，并比较它们各自的优缺点，提出在过渡阶段利用空余口法最为实用和合理。 This paper introduces the composition and working principle of bow mesh detection system installed on electric locomotive. Several methods for determining the ground coordinates of the fault point are discussed, and their respective advantages and disadvantages are compared. It is suggested that the use of the free end method during the transitional phase is the most practical and reasonable.