Abstract: With the analytical method and the finite element method(FEM),the hot-centering process of the billet for rolling seamless steel tube is analyzed,and consequently the tip-cone thrust forces under different process conditions are obtained. Based on the analyses,it is identified that the tip-cone thrust force is in related to such elements as steel type of the billet,centering temperature,thrust speed,friction factor,and size of the centering hole. The deduced formula and relevant calculation can be used for theoretical instructions for type selection of the centering equipment and designing of the dies.