Steel structure nondestructive flaw detection device

The invention relates to the technical field of steel structure detection, and discloses a steel structure nondestructive flaw detection device which comprises a conveying belt and further comprises a U-shaped frame arranged above the conveying belt; the number of the U-shaped plates is two, the two U-shaped plates are symmetrically and fixedly installed at the bottoms of the two vertical edges of the U-shaped frame respectively, and the lower transverse edges of the two U-shaped plates are fixedly installed on the side face, away from the conveying belt, of the conveying belt. The number of the abutting discs is two, and the two abutting discs are both arranged in the corresponding U-shaped plates; the ultrasonic flaw detector is arranged below the transverse edge of the U-shaped frame; and the number of the limiting moving assemblies is two, and the two limiting moving assemblies are installed on the corresponding U-shaped plates correspondingly. The cylindrical steel structure can be automatically rotated