Abstract: Complex seabed geomorphology and the fine structure of marine sediments is a key issue for coastal engineering. It is necessary to collect this useful information in engineering geological investigation for coastal engineering. This paper proposed a set of marine geophysical technology to image water body, seabed geomorphology, marine sediments and unique geological structure with high resolution, on the basis of marine shallow seismic prospecting with high precision. It has been performed in engineering geological investigation of Caofeidian Port, successfully. And the result provides high-resolution images of water body, seabed geomorphology, shallow gas below seabed, submarine faults and landslide. All of these images play an important role in coastal engineering for Caofeidian Port. This successful application indicates this technology is an effective method for geological hazard assessment in coastal engineering.