To effectively suppress or eliminate the misalignment constraint response,the nonlinear dynamic characteristics and vibration mechanism were investigated.For the flexible large range rotating elastic beam mechanism,the Galerkin and Hamilton were applied to establish the dynamics model of the rotating beam.The kinematic constraint equations coupling with parallel misalignment were derived with the help of rotor dynamics theory and the Lagrangian method.Based on the kinematic constraint relationship,the nonlinear dynamics model of the elastic beam under the parallel misalignment constraint was constructed by using the traveling wave superposition principle.The higher-order Runge-Kutta method was applied to analyze the nonlinear dynamic behavior of the elastic beam.The results show that when the speed is 10 rad/s,the misalignment of the coupling has little effect on the dynamic characteristics of the elastic beam.When the speed reaches 150 rad/s,the misalignment increases from 0 to 0.50 mm,the transverse amplitude of the beam increases from 0.18 mm to 10.06 mm,which increases the two orders of magnitude,and the longitudinal amplitude increases from 0.13 mm to 7.30 mm,indicating that there is a strong coupling between the misalignment and system stability at high speed,and its small changes can cause significant sudden and nonlinear excitation.The increase in speed and misalignment can increase the centrifugal force of the coupling with multi-frequency and radial alternation change,causing sudden changes in the external excitation of the rotating beam and leading to rapid destabilization of the system,which is also an important reason that the operation speed of large rotating machinery is not high.