Pneumatic rapid clamping device for circular seam of guide pipe

The utility model provides a pneumatic rapid clamping device for a circular seam of a guide pipe, which comprises a rotary mounting disc, a six-claw pneumatic chuck, a tooth-shaped limiting block, a welding seam supporting claw, a plug, a longitudinal limiting device, an argon nozzle and six pneumatic clamping claws, wherein the six pneumatic clamping claws are arranged on the six-claw pneumatic chuck; an air cylinder on the six-jaw pneumatic chuck controls the pneumatic clamping jaws to do telescopic motion in the radial direction of the disc through compressed air, one end of the six-jaw pneumatic chuck is fixed to the rotary installation disc through screws, each pneumatic clamping jaw of the six-jaw pneumatic chuck is provided with a tooth-shaped limiting block, and each tooth-shaped limiting block is provided with a welding seam supporting jaw; an argon nozzle is arranged above the central axis of the six-claw pneumatic chuck and connected to one end of a plug through threads, and the other end of the pl