Abstarct: In this thesis, a robust control method is presented to control a 3-D Delta parallel robot. This approach is baxsed on a voltage control strategy, While conventional methods are baxsed on the torque control strategy. In the torque control strategy, the dynamics of the actuators is not considered in the control rule for simplicity in the design of the controller, Which reduces control performance at high speeds. voltage-baxsed approach, compared to conventional techniques,is simpler, less computing and more efficient. In this thesis, in order to tracking, by sliding mode control, Using the torque control strategy presented. The sliding mode control method is then presented and compared using a voltage control strategy. The Performance of tracking errors in the present of disturbances and the uncertainties of the system studied in both methods. The stability of the control system is guaranteed by choosing a proper Lyapunov function and the performance of controllers are compared. In order to test stability and robustness of proposed method a simulation has been done with the system model uncertainty which the result shows that this method has good stability and is robust against model uncertainty, The simulation results show the superiority of the voltage-baxsed approach to the torque-baxsed approach.