Abstract: The centering effect of the three-roller steadier has a significant influence on the production quality of the hollow bloom and the shell. Aiming at the three-roller steadier in a certain project，the software SolidWorks is used to carry out motion simulation through the numerical method，and further to obtain the coordinates of the work center during the movement of the roller，so as to intuitively evaluate the centering effect of the device，and at the same time obtain the fitting formula of the stroke of the roller-driving hydraulic cylinder and its opening degree，which provides a good example for the actual engineering application analysis of such type of equipment.