According to the deformation characteristics of three-roll tube rolling, the existent disadvantages of traditional A Geleiyi and A Tselikov＇s formulas were objectively analyzed. An assumption approximate to actual situation was put forward. After suitable simplification, the energy method was adopted to establish velocity fields for permissive movement in deformed areas, and the calculation formula of average unit pressure for three-roll tube rolling was deduced. The values of theoretical calculation are basically consistent with the measured values of large-scale aluminum tube during on-site rolling process. The results proved that the formula is reasonable.
