A parameterized model of a liquid rocket engine thrust chamber was established. Natural frequencies and vibration modes of structure were obtained by finite element method

and verified by modal experiment. Computer numerical design of experiments was conducted by optimal Latin hypercube design in order to get sensitivity of design variables for structural mass and first order natural frequency

which had a guiding significance for the process of optimal design. Multi-objective optimization was carried out using NSGA-Ⅱ algorithm

and the optimal structural parameters were obtained

satisfying both static and dynamic requirements. The mass decrease of the optimal design was 9.1%

meanwhile the first order natural frequency increase was 22.6%. The results show that the proposed method improves the mechanical property of thrust chamber effectively.