Abstract: Local dry underwater welding is one of the important techniques for its economy and flexibleness.Based on the development of local dry automatic underwater welding system, the electrical parameters of welding in air 、5 meters and 15 meters under water are obtained and analyzed by using HANNOVER analysator.The results show that the welding test system can carry out local dry automatic underwater welding successfully and the metal transfer mode during underwater welding is relate to welding environment, which provide experimental foardation for analysing and assessing welding procedure and welding quality of local dry automatic underwater welding.