A new method for the MEMS die package process was reported. Using the method of bionic package, a novel MEMS vector hydrophone was fabricated from a typical mass-beam accelerometer structure. According to the auditory principle of fish’s lateral line and its nature’s fundamental acoustic sensors-stereocilia, a rigidity cylinder was fixed on the center of the mass as a stereocilia, and the sensitivity structure of the hydrophone was obtained. By means of a specific package process, the sensor was fabricated properly for the underwater sound detection application. From the test results of the sensor, we can see that, this vector hydrophone has a receiving sensitivity of -165dB (0dB=1V/µPa, the amplification factor of the preamplifier is 100.) and a good directional pattern in form of “8”-shape. The hydrophone can work well under the maximum pressure of 2MPa.