The combination of vehicle steering system and front suspension system is a dynamic coupled system. In allusion to coupled nonlinear vibration system of a car steering system and front suspension, a high dimension coupled 7-DOF. nonlinear vibration model was constructed using a concentrated parameters method. The nonlinear lateral force of tires, the nonlinear elastic force and damping force of the front suspension and the elastic effect of steering system connective poles were taken into account during the modeling. The dynamic characteristics of the coupled system and the parameter effects of automotive steering and front suspension were illustrated by numerical analysis when the mass unbalance existed in the front wheel, and the vibration relation between the steering system and front suspension was revealed. Research results can provide the theoretical support for dynamic design and synthetical dynamic control of coupled nonlinear vibration system.