Abstract: This paper presents a hydrophone of composite PVDF piezoelectric film cylindrical tube by pour forming. The relations between sensitivity of the hydrophone at low-frequency and the material parameters of each layer are obtained theoretically. Explain how the material parameters of each layer are selected according to different requirements for hydrophone. One can improves performance of hydrophone and simplify working process for the advantage of batch process by pour forming and winding composite film process in this paper. The measured value of developing hydrophone sample shows the hydrophone sensitivity is higher, sensitivity undulation is smailer,acceleration response is very low and performance consistence is well. The experimenntal results of low-frequensy sensitivity agree well with theoretical calculation.