Abstract: The brief introduction covers the main aspects of technical upgrading of the Φ114mm straight forming weld-pipe mill, slitter and galvanizing line, which is located in Laiysng Heavy-duty Machinery Manufacturer, S handong Province and the first of its kind in China, involving the project approachment, mill-selection, project plan fixing and implementation. The evaluation by experts and acceptance after trial production have shown that the upgraded production line’s major technical norms have been up to the level of similar equipment in the world. Aggregated output of four-year operation of the line has been up to 60, 000 tonnes of weld -pipes, producing great profit.