The character is mainly decided by the top configuration of the control system. The system has to have the optimal top configuration if the dynamic performance of electrical-liquid force servo system is contented with the design demand. The electrical-liquid force servo system is changed into the structure of the state space. The top configuration is obtained by analyzing and imitating. The feedback matrix of the top configuration is also obtained

so the top configuration is carried out. The result of imitation indicates that the dynamic performance is improved obviously after the optimal top configuration is realized by the electrical-liquid force and servo system.