Abstract: Along with the unprecedented development of the global economy and oil/gas transport pipeline system construction,the demand for large-sized weld linepipes for oil/gas transport purpose is increased,which has led to the fast development of the large-sized SSAW pipe mills as manifested by the tremendous progresses concerning the manufacture processes and technological level of the equipment. Briefly described in the paper is the newly-made development of the manufacture processes and equipment for large-sized SSAW pipes,covering the equipment for such processes as run-out plate welding,plate trimming,pre-welding,internal/external sub-merged arc welding,expanding,hydrostatic testing and NDT,etc. And technical development of other aspects concerned is also described.