Abstarct: This thesis aims at the optimum design and control of the Stewart parallel manipulator as a motion platform of a flight simulator. A flight simulator's motion platform has to provide a specified translational-orientational workspace to resemble real flight in its range of motion for the pilot. Optimum design of the Stewart parallel manipulator for a desired workspace needs a fast and accurate method to determine workspace during optimization loops. Since the fact that workspace of the Stewart parallel manipulator is dependent in the two translational-orientational subspace. Usually workspace determination and design optimization of the robot is performed in the two subspace of constant-orientation translational workspace or constant-position orientational workspace sequentially. In this Way, current research has proposed a fast and accurate method for constant-orientation workspace determination with integrating geometric and discretization methods. In the following optimum design problem of the Stewart parallel manipulator is demonstrated for a desired cubic shape in the constant orientation workspace. In the optimization problem relative volume of the desired workspace respect to the accupied volume of the robot in the home configuration is considered for physical size optimization. Also, dexterity analysis of the robot is included in the optimization process according to the condition number criterion. Multi-objective optimization problem of the robot is solved as a weighted sum of the mentioned criterions using MATLAB software and results are reported. Finally, proportional-derivative control method with gravity compensation and robust sliding mode control are designed and are simulated for optimized platform of the Stewart parallel manipulator.