Abstract: A kind of underwater arc stud welding gun was developed based on the drawn-arc stud welding technology for underwater quick installation,fixing and other fastening installations. By testing and analyzing the key parameters such as welding current and welding time,lifting height and lifting time,advance gas delivery time and lag gas closing time,the welding quality was effectively improved. The experimental results showed that the technology of underwater arc stud welding could realize the rapid underwater welding of the stud,and it could be applied in the marine engineering such as rapid underwater fixation and installation on ocean engineering.