Abstract: Underwater obstacle detection is an important part of ensuring navigation safety,and the detection of buried objects（such as sunken ships,wreckage,cables,and pipelines）is the foundation of marine economic construction.Among them,detecting submarine cables is the most challenging due to their large regional span,emphasis on shallow surface structures,small pipe diameter,and higher resolution requirements.This project takes the main submarine cable of the H2 wind farm in Sheyang,Jiangsu as an example. By applying several advanced equipment for buried object detection in the industry at present（3D sonar system,multi frequency synthetic aperture sonar system,shallow subsurface profiling system）,the old submarine cable routing water area is rechecked for detection,in order to understand the surrounding water depth and seabed terrain,determine obstacles such as broken pipes and residual pipes that affect navigation safety,provide a basis for port planning and construction and port navigation services,and provide technical support for submarine cable maintenance.