Abstract: A transient model during the water lubrication tilting-pad thrust bearing start-stop process was established in this paper, the Hertz contact model was used to calculate the deformation of thrust bearing pivot, the initial tilting speed U_ft which was the speed of tilting-pad thrust bearing began to rotate during boot process was defined. The influence of the contact and wear deformation and the load on the water lubricated tilting-pad thrust bearing during boot process were analyzed. The initial tilting speed U_ft increased with the pivot deformation increased and the load increased. Giving a limit value of the initial tilting speed U_ftc of the tilting-pad thrust bearing, the load and bearing deformation had the maximum value when the geometric dimension of the tilting-pad thrust bearing was determined. The test rig for water lubrication tilting-pad thrust bearing was used to verify the numerical model. The results show that the U_ft measured in test were consistent well with that of numerical analysis, and the error was less than 10%, the combined method of acceleration sensor and torque sensor accurately determined the initial tilting moment of thrust pad, thereby determined the speed U_ft.