The API-X60 seamless pipeline perforation after 14 years of service for gas gathering. The perforate causes were analyzed by the thickness detection (TD) nondestructive tester (NDT), direct-reading spectrometer, tensile strength test machine, impact test machine, Vickers hardness tester, optical microscopy (OM), macroscopic fracture morphology, scanning electron microscopy (SEM), and energy spectrum analysis (EDS) in this paper. The results show that the perforation is caused by the transmission medium containing carbon dioxide, oxygen, and chloride ions. Water accumulation is easily to form at the 6 o’clock position of the pipeline, resulting in corrosion involving carbon dioxide and oxygen, and finally perforation. It is suggested to inject corrosion inhibitor into the pipeline, corrosion monitoring and internal inspection the pipeline, and conduct risk assessment.