In this paper,characteristics of friction stir welding and its preliminary application in domestic electric power products are briefly introduced. In the development of large diameter GIL shell,after comparing the spiral welded pipe and longitudinal welded pipe structure,it is found that the spiral welded pipe has the advantages of high production efficiency and low welding stresses. In view of the spiral tube structure,a double side welding scheme is designed,and the experiment of friction stir welding is carried out,the suitable welding parameters are obtained then. The first aluminum alloy spiral tube in China has been successfully developed by using the self-developed spiral pipe welding equipment combined with advanced friction stir welding technology.