Signal aliasing is a key problem in applications of modern sonar systems based on fiber-optic hydrophones. Preliminary experimental results have shown that the acoustic low-pass filtering fiber-optic hydrophone is a simple and effective anti-aliasing scheme. We construct the low frequency lumped parameter model of acoustic low-pass filtering fiber-optic hydrophone based on the theories of electro-acoustic analogy. The frequency response of the fiber-optic hydrophone is estimated using the circuit analysis method. Theoretical results show that the fiber-optic hydrophone system has the similar response characteristics as a classical two-order low-pass filtering circuit. A simple low-pass filtering fiber-optic hydrophone is designed and manufactured to test the theory. And the acoustic sensitivity frequency response is measured in a standing-wave tube. Experimental results are, on the whole, in agreement with the numerical values. The low frequency acoustic sensitivity is about -141.5 dB. The measured resonant frequency is 985 Hz, which accords well with the theoretical value of 1270 Hz. The acoustic sensitivity at resonant frequency is -126.8 dB, and the attenuation rate is about 20 dB/octave. The attenuation beyond 3 kHz is bigger than 20 dB.