Abstract: To meet the requirement for low power consumption, low noise and wide band, a self-contained underwater acoustic signal acquisition circuit is designed. In order to improve the signal to noise ratio (SNR) and reduce power consumption, two-port noise analysis and fully differential design are used in analog circuit, and the operating voltage of the analog circuit is reduced to 3 V. Bessel filter and Chebyshev filter are combined to reduce 1/f noise and high frequency irrelevant noise. In the digital circuit section, ZYNQ embedded extensible processing platform is used instead of traditional micro control unit (MCU) and field programmable gate array (FPGA). Phase locked loop (PLL) core is used to change the sampling frequency according to the operation frequency band, and double first in first out (FIFO) block is used to write data to trans flash (TF) card, so that the digital signal is transmitted and stored at a higher rate. By simulation, the analog circuit achieves a gain of 52 dB within 60 Hz to 58 kHz. The measured results show that the analog circuit power consumption is 95 mW, the digital circuit power consumption is 1.9 W; when the sampling rate of analog/digital (A/D) chip reaches 128 kHz, the self-noise spectrum of the circuit is slightly higher than -110 dB, and the root mean square (RMS) of total noise is 961 μV. The acquisition system with large capacity TF card can meet the needs of self-contained hydrophone to collect acoustic signals continuously for a long period.