Abstract: The acceleration sensitivity is a significant parameter for a fiber-optic hydrophone used in towed line arrays. A new simulation method of acceleration sensitivity of fiber-optic hydrophones based on FEM harmonic analysis and the strain-optic effect is reported. The influence of different excitation positions and support shell material parameters on acceleration sensitivity is analyzed. The results show that a slight deviation of excitation position from the center of the hydrophone will cause a sharp increase in the acceleration sensitivity. Increasing the elastic modulus, wall thickness, or reducing the density of the supporting shell material will result in lower acceleration sensitivity of the hydrophone under the same installation conditions. It is indicated that using the finite element method to analyze the acceleration sensitivity of fiber-optic hydrophones can provide important theoretical guidance for reducing the acceleration sensitivity.