In order to accurately describe the dynamic characteristics of the rocket launcher high-low level adjustment, the dynamics simulation analysis of rigid-flexible coupling is carried out. Based on the theory of rigid-flexible multi-body dynamics, the rigid-flexible coupled dynamics model of rocket launcher was constructed by SolidWorks, ANSYS and ADAMS software. The model is tested and parameterized, and simulated and compared with actual working conditions. The landing gear stress concentration area was determined. The simulation results show that the study can accurately reflect the dynamic performance of the rocket’s high-low profile guns, and provide data support for the motion accuracy and reliability analysis of the high and low follow-up, and provide reference for the design optimization of the high-low servo device.