Abstract: The stress and displacement distributions of the impeller,in flow-field of liquid ring vacuum pump,were mathematically modeled,theoretically analyzed and numerically simulated with Pro/Mechanica for design optimization.The influence of the structural parameters of impeller blades on the impeller behavior,including the pumping speed of air and mechanical properties,such as the stress and displacement distributions and rigidity,was investigated in iteration simulation to specify the highly sensitive parameters.The preliminary results show that there exist 14 influencing structural parameters.When it comes to minimization of weight under the design requirements,the structure and density-profile of 6-parameters were optimized via simulation.The results show that while satisfying the design requirements on pumping speed and mechanical behavior,the optimized impeller losses a weight by 1.5%,from 82.6 to 81.3 t.