Ultra-long thin wall longitudinal joint welding device

The utility model provides an ultra-long thin wall longitudinal joint welding device which comprises a headstock (1), a tail support (2), a compressing beam (3), a central spindle (4), a key tool (5), a welding gun traveling guide rail (6), a key airbag (7), a welding gasket (8) and a central spindle locking device (9). The ultra-long thin wall longitudinal joint welding device has good structural rigidity; the rigidity requirement for assembling and welding of an ultra-long longitudinal joint is ensured; the maximum longitudinal joint welding length exceeds 6,000mm; welding of an ultra-long barrel can be completed for once; the number of weld joints is effectively reduced; assembling and correcting working intensity is reduced; production efficiency is improved; the thin wall barrel (the thickness of the barrel is 1mm to 6mm) can be welded; and by utilizing the pneumatic key tool, consistency of assembling of the thin wall barrel is effectively ensured.