Based on multi-body dynamics, a whole car model with rigid-flexible coupling suspension that included the flexibility of lower arms and stabilizer bars was established by using ADAMS/Car software, and the flexibility of elements has been obtained with FEM. The analyses for the accelerations of floor and lower arm, the dynamic deflection of suspension, and the dynamic deformation were carried out. The research result showed that the PSD of vertical acceleration of body and the PSD of vertical acceleration of lower arm reduced by 21.5% and 71.3% respectively, compared with rigid model. In addition, the dynamic load of tire decreased by 21.5%, and the working space of suspension increased form 15% to 20%. The research result also showed that the difference between rigid body model and rigid-flexible coupling model rose with velocity. The analysis demonstrated that the flexibility of suspension components could not be neglected.