Abstract: A novel flux-cored wire for underwater wet welding was developed. The underwater wet welding experiments with the water depth of 30 m were carried out by using a simulated pressure vessel and automatic welding machine. The experimental results show that welding process was stable and the good weld appearance could be obtained. According to the ANSI/AWS D3.6 1999,the tensile strength,bending property,hardness and impact toughness of the joint were studied. The results indicated that the fracture location of tensile test was in base material, no fracture was occurred during bending test and the acceptable impact toughness of joints about 30.25 J/cm² at 0℃ were also obtained. So the novel flux-cored wire could reach the requirements of underwater wet welding for CCSE36 steel with the water depth of 30 m.