In order to choose an appropriate suspension method of equipment under car for higher-speed test EMUs, the rigidflexiblecoupling multi-body dynamics SIMPACK model of the higher-speed test EMUs was built to analysis the coupled vibrationbetween carbody and the equipment under car. Different suspension methods had also been tested by the rolling rig test. Both thesimulation and experimental results show that, for the large mass equipment under car, the elastic suspension method is better than therigid one in dynamic performance. For the elastic suspension method, the larger dynamic and static stiffness ratio is more reasonable.