Considering influence of the impact effect of new generation light high mobility rocket on the vertical vibration of the vehicle body during the launch process,a 4-DOF mathematical model of 1/2 launcher was built based on the two-shaft interconnected hydro-pneumatic suspension,the simulation models with three-ways including tire support,mixed support and outrigger support were built by AMESim software.The results show that the response of the rocket launcher system under the pure tire support is poor,and the amplitudes of the vertical displacement and vertical acceleration of the vehicle body are large,which are not conducive to the rocket launch,while the system responses are better under the mixed support and pure outrigger support conditions.