Abstract: Due to the mutual constraints among the various performance indicators of hydrophones, as well as the complex multivariate functional relationships with structural parameters, this paper proposes a multi-objective optimization design method for hydrophones. In this method, the structural parameters are taken as variables, the sensitivity and equivalent noise indicators are adopted as the objective functions, and the operating frequency band is set as a constraint condition. Based on constrained optimization, this method utilizes the multi-physics coupling advantages of the finite element method. By constructing a weighted objective function that incorporates the constraint conditions, rapid and effective optimization of hydrophone structural parameters within a preset range is achieved. Using this method, a simulation-based optimization design is carried out for the commonly used bending disc and cylindrical hydrophones. The results show that within the same operating frequency band, the comprehensive performance indicators of both hydrophone structures designed with PZT-8 are superior to those with PZT-5A. Meanwhile, hydrophone samples made of different materials are developed using the cylindrical structure as an example, and the test results verify the effectiveness of the proposed method.