Abstract: The different dosages of D101 polystyrene macroporous resin beads modified polyurethane/epoxy elastomer composites(D101/PU-EP) were prepared by the casting method, and their acoustic properties were studied. The bulk moduli and shear moduli of the D101/PU-EP elastomer composites were calculated from hollow spheres containing coating-foam composite modulus prediction model based on equivalent inclusion principle. And then combined with the calculation of the modulus of the acoustic model simulation results, the underwater acoustic performance of D101/PU-EP elastomer composite was theoretically simulated by transfer matrix method, and the effects of D101 content and gradient structure on the underwater acoustic properties of macroporous resin beads of the composites were obtained, and meanwhile the underwater acoustic properties of this composites were measured by underwater acoustic material sound pulsetube system(test in tube, water backing condition). The results show that D101 macroporous resin beads can improve the underwater acoustic absorption properties of the composites effectively, the average acoustic absorption coefficient of the composite with three-layer gradient structure(the average acoustic absorption coefficient of 10% content of D101 composites is 0.53, and maximum is 0.64) is higher than that of the single-layer structure composite(the average value is 0.46, and maximum is 0.52) containing the same contents of D101, and the numerical examples show underwater acoustic properties experimental results of D101/PU-EP elastomer composites are basically consistent with the acoustic model simulation results.