Abstract: Owing to the rapidly increased domestic demand of electric energy, the domestic production capacity of the large-sized, heavy-wall seamless steel tubes is far from satisfaction to the current market demand, and this situation has led to import of most of the tubes of such kind ranging from Ф159 mm to Ф1 066 mm.De-scribed here in the article is the technology of forging-boring process for hi-pressure boiler-purpose large-sized, heavy-wall seamless steel tube as adapted by the Special Steel Tube Plant of Inner Mongolian Beifang Heavy Industrial Group Corp.Described are the manafacture process and equipment technology of the said tube.Also analyzed are the quality and characteristics of the seamless steel tubes as produced by the said maker with the above mentioned forging-boring process based on the results of different property tests of the finished products.Show that the laid tube is of consistent quality with all the property targets up to or even higher than the requirements of applicable standard.