The study of rotor dynamic stability of hydraulic turbine system has become extremely important because of the increasing capacity, size, and inertia of large turbines. Crown clearance and band clearance in hydraulic turbines will influence the rotor dynamic characters of turbine shaft system. In this article, the character of the turbine shaft system under different clearance parameters is studied in order to observe how the clearance parameters influence the stability of hydraulic turbine. The relationship between the hydraulic turbine stability system and the turbine clearance structure is also analyzed. In this study, the force on the turbine rotor induced by fluid flow in clearances is described with the analytical solution of Reynolds equation obtained in the article, in which the fluid flow is considered to be incompressible and isothermal. And, the rotor dynamic character of the turbine system is calculated by NewMark direct integral method and non-linear forces obtained from Reynolds equation are implemented. Finally, principles related to the clearance parameters influencing the rotor dynamic character of turbine system are summarized.