Based on the preliminary analysis of the change mechanism of the turbine blade tip clearance, the simplified model of blade, rotor and casing is established. The radial changes of rotor that bring by rotate speed and engine start transient state temperature is simulated. And the effect of rotor vibration amplitude of aero-craft in-flight maneuver state is discussed. The results show that vibration amplitude and radial displacement of rotor have a great effect on the turbine tip clearance.