Marine pipeline welding auxiliary device

The utility model discloses a marine pipeline welding auxiliary device which comprises a machine frame, two sets of adjusting mechanisms arranged on the machine frame and two sets of bracket assemblies arranged on the adjusting mechanisms and further comprises driving mechanisms arranged on the adjusting mechanisms. The driving mechanism comprises a driving part, a transmission part arranged at the output end of the driving part and two displacement mechanisms arranged at the two ends of the transmission part correspondingly. The two displacement mechanisms can be driven by the driving part and the transmission part to get close to or get away from each other. Each bracket assembly comprises a fixing frame, the fixing frames of the two bracket assemblies are connected with the two displacement mechanisms correspondingly, and rotating rollers are rotationally connected to the fixing frames. When a pipeline with a small size and diameter needs to be welded, the driving piece is controlled to drive the transmiss