In order to study the dynamic performance of tiltrotor aircraft nacelle tilting mechanism during nacelle turning from wing aircraft model to helicopter model, based on the force and kinematic analysis of nacelle tilting mechanism, the nacelle tilting mechanism multi-body dynamic simulation model was established on the LMS Motion software platform, defined every components property of nacelle tilting mechanism, created joints between the components, defined motion drives, created external forces and torques to simulate real working condition, to obtain and analyze the major kinematic parameters curves of nacelle and the interaction forces between nacelle and screw shaft. The results can indicate: With the increase of nacelle rotation angle, the interaction force between nacelle and screw shaft decreases then increases, the interaction force between nacelle and wing increases.