Abstract: In order to study the problem of interior noise prediction of sonar dome under mechanical excitation, the method combining numerical method (FEM-BEM) with experimental method is used to study the interior sound field of the sonar dome. Firstly, the sonar dome model is built based on the actual model. Then the numerical calculation is carried out with the mechanical excitation applied on the model and the mean square sound pressure of interior sound field can be obtained, and then the experiment is made in a lake. Finally, the numerical calculation results and experi-mental results are compared. The research shows: the method of FEM + IBEM is valid for studying the coupling problems of structure and sound for a close system, for example, the inner sound field of a sonar dome. The experimental results are in accord with simulation results; the ratio of mean square sound pressure to mean square vibration velocity represents the inner average sound field characteristic of a dome shell structure and can be used to compare and analyze the results of numerical calculation and experiment.