The invention discloses a contact line wear detection device. The device comprises: a first image collection unit and a second image collection unit, which are both disposed under a contact line, respectively collect images of the contact line from different positions, and coincide in an image collection region on the contact line; an image processing unit, which recognizes wear edge points according to the images of the contact line, and determines position information of the wear edge points; and a calculation unit, which calculates the wear amount of the contact line according to the position information of the wear edge points. Compared with existing manual detection methods, the device can greatly improve contact line wear detection efficiency, and avoid missed detection.