Abstract: Aiming at the problem of improving input precision of dynamic parameter in the design of underwater acoustic materials, a method of accurately testing the complex Young’s modulus and Poisson’s ratio is proposed. By introducing the Williams-Landel-Ferry (WLF) equation into the Havriliak-Negami (H-N) model, the trust region reflection algorithm is used for unknown parameters fitting to obtain the master curves of material parameters in a wide frequency domain. For the Poisson's ratio test, based on the unique quantitative relationship between Poisson's ratio and apparent Young’s modulus ratio of the same material with variable shape factors, the quantitative curves of apparent Young’s modulus ratio and Poisson's ratio are obtained only by performing the finite element simulation on two samples with different shape factors under static compression. Therefore, according to the measured result of apparent Young’s modulus of rubber sample, the Poisson's ratio can be directly obtained by local weighted regression. The aforementioned material is used to make an acoustic tube sample with a diameter of 55 mm and a thickness of 50 mm for testing its sound absorption coefficient. At the same time, the measured results of complex Young’s modulus and Poisson’s ratio of rubber are input into the water-rubber-water layered medium model to calculate the sound absorption coefficient, which is in consistent with the result of acoustic tube test. Therefore, the correctness and effectiveness of the test method mentioned above is verified.