Based on the cavity acoustic characteristics of dynamic subsystem modification methods, treating the automotive powertrain mounting systems as subsystems attached to the body, revealed the direct ration relationship of interior noise pressure and the stiffness, damping characteristic parameters of mounting elastic component. And in order to ensure efficiency and reduce the solution of environmental requirements, response surface methodology used to approximate treatment. Furthermore, to reduce vehicle interior noise pressure as the objectives and the stiffness, damping characteristic parameters of mounting elastic component for the design variables, established the mounting characteristic of acoustic optimization design model. Finally, taking 5t rough terrain container forklift truck for example, showed that the optimization of the design method is effective.