With the overall consideration of the various performance of the parallel robot (e.g. workspace, dexterity, bearing capacity, stiffness, etc.), a basic procedure was carried out for the multi-objective optimization with the example of 3—UPS—S based on the integration of Matlab, Pro/E, ANSYS by Isight, and a multi objective dimensional synthesis was carried out for the parallel mechanism. Thus, a method was proposed for the multi-objective optimization of parallel mechanism based on Isight. The result of the analysis indicated that the proposed method could automatically solve the kinematic and dynamic performance, achieve modeling and finish the finite element analysis for the design of experiments and multi-objective optimization with the integration of the engineering software. Through the Pareto graph and the Pareto front obtained, the designer could select the appropriate optimal solution for the parallel mechanism with more information.