Crack positioning detection device

The utility model discloses a crack positioning detection device which comprises a steel ring, the surface of the steel ring is sleeved with a plurality of crack detection mechanisms, each crack detection mechanism comprises an equipment box, a central groove is formed in the equipment box, an ultrasonic detector is fixedly installed in an inner cavity of the central groove, and a detection head is fixedly installed at the bottom of the ultrasonic detector. An ink pump and an ink return pump are fixedly mounted on the two sides of an inner cavity of the mounting groove correspondingly, a bottom groove is formed in the bottom of the storage groove, an inner cavity of the bottom groove is fixedly connected with a marking box, a lifting groove is formed in the marking box, an inner cavity of the lifting groove is slidably connected with a lifting plate, an embedding groove is formed in the bottom of the marking box, and a marking seal is placed in an inner cavity of the embedding groove. The bottom of the liftin