Abstract: Based on the idea of vertical divergent magnetic field making arc moving along the stud inwall, a new hollow stud rotating arc welding technology is presented.For hollow studs with outer-diameter of 12 mm and wall thickness of 3 mm, the homogeneous revolution of arc along stud wall is realized.Welding process experiments show that the process parameters of rotating arc stud welding are obviously greater than the same outer-diameter solid stud, and the welding technology normalized window is bigger, but narrower than that of solid stud.The optimum parameter of rotary arc current is 1-2 A, welding time is over 600-700 ms, welding current is 800-900 A.Joint performance testing results show that the formation of hollow stud welded joint is full and good.Macrostructure detection results show that there are no defection such as incomplete fusion, slag and porosity, the interface fusion rate reaches 100%, and the interface strength maintains at 370-410 MPa.