Detection mechanism and wheel out-of-roundness detection device

The utility model relates to the technical field of train vehicle detection, and discloses a detection mechanism and a wheel out-of-roundness detection device, which comprise a detection plate, a mounting seat and an elastic body, the mounting seat is connected with the lifting adjusting mechanism and is provided with a groove; at least part of the detection plate is movably arranged in the groove; the elastic body is arranged in the groove and located between the groove and the detection plate. According to the detection mechanism and the wheel out-of-roundness detection device provided by the utility model, when the wheel presses the detection plate, the detection plate is passively pressed and descends, so that the elastic body is subjected to a downward pressing force and stores elastic potential energy, and therefore, after the wheel is driven away, the elastic body can release the stored elastic potential energy to enable the detection plate to recover to the original height, and the detection accuracy