Abstract: Along with the recent unprecedented development pipeline construction industry and the global economic development and change,the large-sized LSAW pipe mills including UOE mills,PFP millis and new type RB mills have been widely used,relevant new technologies are springing up,the product application scope there-of is increasingly expanded,and product quality improved continually.Briefed in the article are the general situation in respect to construction of large-sized LSAW mills and progress of relevant formation technology as well.