Abstract: A composite piezoelectric effect sensor was designed based on the principles of flexible piezoelectric films for the measurement of shock wave signals. To investigate the impact of sensor substrate configurations on its measurement performance, different substrates with varying aperture sizes in the deformation region were prepared. This allowed for the adjustment of the deformation modes of the piezoelectric film, thereby controlling its performance in measuring shock waves. Experimental results reveal that increasing the aperture size of the polyvinyl chloride（PVC） substrate significantly enhances the sensitivity coefficient of the polyvinylidence fluoride（PVDF） film sensor. Moreover, as the diameter of the deformation region increases, the signal’s pulse width also increases accordingly. Finally, through explosive experiments, the influence of the PVC substrate on the signal of the PVDF film sensor was studied, confirming the accuracy of the PVDF sensor with an 8mm deformation region diameter in measuring explosive shock waves. This study provides valuable insights for future selection of PVC substrate deformation regions in PVDF film sensors.