To further expand the working frequency band of the distributed feedback (DFB) fiber laser hydrophone, a 13-mm-diameter encapsulated structure with sensitivity enhanced through polyurethane end surface pulling is presented. The theoretical model of the relationship between acoustic pressure sensitivity and polyurethane material parameters is established. After the relationship between the dynamics performance of hydrophone and polyurethane material parameters is simulated, the parameters of the two-component polyurethane are optimized. Prototypes of the hydrophone are fabricated and tested. The acoustic pressure sensitivity reaches (-137.60±2) dB in the frequency range of 10~20000 Hz, which shows that the working frequency band of the hydrophone is expanded through polyurethane end surface pulling and it can well meet the requirements for the engineering application of towed line arrays.