Abstract: Aiming at the burst failure of a long-distance river crossing gas pipeline, the causes of the accident are analyzedby fracture morphology, nondestructive testing, chemical composition, microtexture, mechanical performance analysis andfinite element simulation. The results show that the pipeline segment was stressed a concentrated load in the process ofbacktow with blank pipe during river crossing, which led to pipeline deformation under local stress, finally partial buckling.There was a significant stress concentration at the buckled deformation part during gas delivery of the unstable gas pipeline, leading to the extension of micro-cracks from deformation hardening at the outer wall and the failure of the pipeline at last.Therefore, crack extension and anticorrosion coating break caused by instability of the pipeline is the main reason behind theburst failure of the pipeline.