Abstract: In order to ensure the safe operation of subsea pipelines, it is necessary to perform inspection periodically. However, there are many constraints in the traditional detection methods, which limit the frequency and efficiency of subsea pipeline inspection. For this reason, a subsea pipeline detection system based on the Unmanned Surface Vessel (USV) was proposed. The system, with a subsea pipeline detection system installed on the USV, is capable of realizing offshore operation under the remote control of person on shore and inspecting the pipelines with autonomous navigation. The USV-based subsea pipeline detection system is composed of a USV subsystem, a subsea pipeline detection system and a data processing and presentation system. The system realizes subsea pipeline detection based on navigation and positioning, presetting tracks of USV survey line, 3D imaging sonar and sub-bottom profiler. Currently, the USV-based subsea pipeline detection system has been used for the pipeline detection of Chengdao Oilfield in Shengli Oilfield, and scanning inspection was performed for most of the pipelines, obtaining the length and height of the bare pipelines and the suspended pipelines, which can further improve the efficiency of subsea pipeline inspection and provide a new method that is safer, more intuitive and faster for inspection of subsea pipelines.