Marine riser detection and conveying device and detection system

The invention discloses a marine riser detection and conveying device, which comprises a conveying main body, at least three cross runners and a reciprocating motion unit, wherein the conveying main body comprises two semi-circular shells with one sides being hinged in the axial direction and the other sides being provided with hasp switches; the cross runners comprise stepped shafts, connecting sleeves capable of being arranged on the stepped shafts in a rotating manner, and radially elastic clamping wheels connected to the connecting sleeves; the two ends of the stepped shafts are arranged on the inner walls of the semi-circular shells; the reciprocating motion unit comprises a guide pipe, a ball receiving switch and a ball throwing switch; the guide pipe is positioned at a detection starting position and used for accommodating counterweight balls therein; the ball receiving switch is arranged on the guide pipe and emerges from the water under the action of the ball throwing switch to automatically receive