In view of introduction of the composition and principle of the electro-hydraulic position servo control system, the mathematic model of the system was built. A fuzzy-PID controller was also designed by combining fuzzy logic control and PID control, for which the parameters of the PID controller can be adjusted on-line by the output of the fuzzy controller. Comparing PID controller with fuzzy-PID controller, the simulation results proved that the fuzzy-PID controller can improve the property dynamic and stabilization of the system by MATLAB software.