Titanium alloy TC11 rods with Ф25 mm, were rolled to that with Ф17 mm in four passes by a triangle-round-triangle-round sequence. The rod temperature drop was measured at entry temperature 950 °C during continuous rolling, and the rolling forces and the roll torques were measured in the case of different area reductions at 750, 850, 950, and 1050 °C. Then, the geometry shapes of deformation zone were analyzed for different passes. The mathematic model of the rolling force for Y-type mill was modified based on empirical modifications of two-roll theories. A number of experiments were also carried out to check the validity of the proposed mathematic model. The result shows that the difference between the calculated value and the experimental value is relatively minor. Therefore, this mathematic model can provide the foundation for theoretical research and engineering application of Y-type rolling process