Development of special rubber shock absorber test equipment for vehicle will become very important, this equipment can test and analysis of dynamic characteristics for rubber shock absorber.The paper discusses the problem on optimum design of electro-hydraulic servo system which drives the vibration set. A closed system for controlling mechanical position or motion using feedback from the electro-hydraulic servo valve of the device as an input has been used in hydraulic servo system. The maximum region of design parameters has been defined for hydraulic servo cylinder as a core element of the electro-hydraulic exciting system. Established the mathematical model of the system, and the dynamic characteristics of the hydraulic servo cylinder are investigated by utilizing the simulation software MATLAB. The results of computer emulation show that this method is practical.