Abstract: To explore underwater wet welding in the field of modern industry application prospect, common problems of underwater wet welding were briefly introduced, such as hydrogen induced crack, poor quality of welded joint and unstable welding process. Improving principles and methods of underwater wet welded joint quality were introduced. The research progress of controlling the diffused hydrogen content of underwater wet welded joint, improving strength of the joint and the stability of welding process were mainly introduced. Underwater wet welding process for the future development was prospected in engineering practice.