Equivalent self-noise is an important performance indicator for micro-electromechanical systems(MEMS) piezoelectric vector hydrophones, and the noise of the preamplifier circuit is an important consideration.This study entailed the design of a low-noise preamplifier circuit to reduce the self-noise of MEMS piezoelectric vectorhydrophones. By using a circuit structure with dual junction field-effect transistors (JFETs) in parallel and supplementingit with appropriate bias circuits, a theoretical analysis of different noise sources was conducted to optimizethe circuit parameters. The design and fabrication of a low-noise preamplifier circuit with superior noise performancewere ultimately achieved. The test results show that, within the operating frequency band of the MEMSpiezoelectric vector hydrophone, the low-noise preamplifier circuit amplifies signals without distortion, with a voltagegain of 43.8 dB and an equivalent input noise voltage spectral density of 0.7 nV/ Hz@1 kHz. This noise performanceprovides evident advantages over similar amplification circuits domestically and internationally.