The invention provides a device and a method for measuring phase difference between vector hydrophone sound pressure and vibration velocity. The device of the measuring vector hydrophone sound pressure vibration velocity phase difference comprises a vibration table, a vibration table controller, a signal generator, a data collection system, a supporting device, a water drum and an acceleration sensor. The signal generator is connected with the vibration table through the vibration table controller, the data collection system comprises an upper computer and a data collection device which are connected together, the acceleration sensor is connected with the data collection device, and the supporting device comprises a vibration seat which is fixed on the vibration head of the vibration table. Vibrational excitation is generated by using the vibration table, the phase differences between the sound pressure hydrophone and a vibration velocity sensor in the vertical direction and the horizontal direction are respectively obtained, the fact of manually adding modification values to measured parameters is not needed, and the measuring process of parameters of the vector hydrophone is effectively simplified, and due to the fact that the phase difference measuring device of the vector hydrophone sound pressure vibration velocity is simple in structure and low in manufacture cost, and the phase difference measuring device of the vector hydrophone sound pressure vibration velocity is enabled to be popularized and used easily.