An ideal positioning servo system should accelerate the rotor of servo motor by its maximum acceleration torque and stop at the target position without overshoot. When the positioning servo system has no ideal profile of position reference, the conventional positioning servo system cannot realize the ideal high speed positioning response. In order to overcome this problem without the ideal profile of position control, this paper proposes a new high speed positioning servo system using integrator correction of PI controller based on disturbance observer. The proposal method corrects the integrator value of its minor PI speed regulator by using the torque current reference estimated by disturbance observer. The experimental results confirm that the proposed high speed positioning servo system attains the fine and smooth high speed positioning response with the shortest settling time.