Sliding shoe centering mechanism, steel rail flaw detection device, steel rail flaw detection system and steel rail flaw detection car

The embodiment of the invention provides a sliding shoe centering mechanism, a steel rail flaw detection device, a steel rail flaw detection system and a steel rail flaw detection car, and relates to the field of rail flaw detection. The sliding shoe centering mechanism comprises a base, a frame, a sliding shoe and a magnetic assembly; the frame is in sliding fit with the base in the first direction, the sliding shoes are arranged on the frame, and the magnetic assembly is arranged on the frame and used for attracting the steel rail to drive the frame to slide relative to the base in the first direction, so that the sliding shoes move along with the frame to be centered with the steel rail. The sliding shoe centering mechanism enables the sliding shoe to be capable of follow-up adjustment in the process that the steel rail flaw detection device moves along the steel rail and always keep centering and contact with the steel rail, so that normal flaw detection work of the steel rail flaw detection device is gua