The crystalline structure change and dielectric performance of microwave-irradiated PVDF/PZT composites were studied by FTIR, DSC, DMTA, and DEA. The dielectric analysis suggests that the dielectric permissivity and loss reduce, which is useful for improving the sensitivity of composites used in passive transducers. The structure analysis results show that the microwave irradiation promotes crystalline transformation of PVDF from alpha to beta; The crystallinity of PVDF in PVDF/PZT composites increases and Delta T decreases; the DMTA measurements illustrate that the value of E' and tan delta peak increases after irradiation.