The problem of dimension reduction of highdimensional nonlinear systems with multiple parameters was addressed in terms of structural characteristics of the system.The dimension reduction approach based on the fixed interface component mode synthesis of substructures was employed to analyze the system,and then an order reduction for the entire nonlinear system was proposed along with the process of sensitivity analysis.First the system was divided into a number of subsystems according to the characteristics of practical structure,some of which are linear subsystem,and the remains are nonlinear. Then the frequencies and modes related to parameters of the linear subsystems were derived from the sensitivity analysis theory.Finally lower dimension nonlinear dynamic systems with multiple parameters were obtained by synthesizing the nonlinear subsystems and the modes truncated from the linear subsystems in terms of the fixed interface mode synthesis.Numerical example was given to illustrate the effect of the proposed approach.