Abstract: With the continuous development of ocean resources and the ongoing changes in the marine environment, underwater target detection and corrosion assessment have played a significant role in fields such as marine engineering, ocean resource exploitation, and maintenance of underwater infrastructure. Although these two technologies follow different paths, they intersect and were found to be interrelated to a certain extent. The current developments of the application of deep learning technology in underwater target detection and corrosion assessment in recent years were reviewed. It introduced the background of underwater target detection and corrosion assessment was introduced, and then the current state of application of deep learning technology in both underwater target detection and corrosion assessment was analyzed. Finally, the potential challenges of underwater target detection and corrosion assessment under the influence of deep learning was discussed, as well as future research directions.