In order to improve the suitability of the fiber hydrophone towing line array, a flexible fiber grating hydrophone array was proposed.The sound pressure sensitivity of three flexible fiber grating hydrophones was calculated according to the mechanical theoretical model, and the influence factors were compared and analyzed. 2-element flexible fiber hydrophone sample arrays with diameters of 10 mm,12 mm and 16 mm were developed through finite element simulation for frequency response analysis. The sensitivity was measured by a vibration liquid column experiment. The experimental results show that the response is flat within the frequency range of 200~800 Hz, and the average sound pressure sensitivities of the hydrophone arrays with different structural parameters are -138.90 dB, -134.71 dB, and -136.12 dB, respectively. The theory and simulation analysis are verified. By further optimizing the material and structure parameters and using weak reflection fiber grating, an integrated flexible hydrophone array with hundreds of elements can be constructed according to the design in this paper.