Thepolyvinylidene fluoride (PVDF) piezoelectric film has good piezoelectric effect and is widely used in the field of vibration measurement and so on.In this paper, by analyzing the circuit model of PVDF piezoelectric thin film, a preamplifier module matching the circuit is designed, analyzed theoretically and testedexperimentally in this paper. The testing results are consistent with theoretical ones.The contrast test of the flow field information of the circular tube was carried out by using the preamplifier modulewith PVDF piezoelectric film.The experimental results show that the measurement of the internal flow field by using PVDF piezoelectric film is superior to the accelerometer at the low frequency range.It can measure abundant lowfrequency components, and provide a good experimental basis for analyzing the flow field in the tube.