Abstract: Statistics and classification of typical welding quality problems present at the construction sites of two representative ships and two representative offshore platforms are carried out.The results indicate that welding processes and materials account for a relatively high proportion of the problems,accounting for nearly eighty percent.The manifestations,hazards,and causes of high-frequency problems such as non-preheating,preheating and interpass temperature,welding consumables baking,welding cleaning not meeting requirements,and process parameters exceeding the range are emphasized.Improvement suggestions are proposed to prevent and reduce the occurrence of welding quality problems during construction,and to provide reference for ensuring and improving the welding quality of ships and offshore platforms.