Abstract: This paper discusses the reasons for subsea pipeline failure in China and abroad, including improper design, inadequate quality of pipeline material, imperfect pipeline construction, erosion and suspension, anchoring operation of ship, ship stranding, impact of dropped objects, sand production leading to suspension of subsea pipeline, fishing with trawl, internal and external corrosion, equipment failure and operational mistakes. This paper presents the ROV-based inspection technology of subsea pipeline, which has evident advantages in terms of working depth, carrying capacity and adaptability to complicated sea conditions. ROV carries the inspection equipment to conduct the pipeline inspection, in a way that ROV navigates along the sailing line for regular inspection and stop at the questioning or failure point to conduct fine inspection, or even underwater interference.