A digital position servo controller for the Electro-hydraulic system is proposed based on robust integral structure control (RISC) scheme. The main aims of the proposed system are to enhance the performance while driving the servo machine rod to track a sine-wave or step command. According to the state feed-back theorems, a simplified plant model of the Electro-hydraulic is conducted. Close-loop characteristic function of the control system will be assigned on the stable plane to ensure the state variables so that it can rapidly converge to stable point. The design steps and theoretical analysis will be described in detail. Both simulation and experimental results are shown for proving the performance.