Abstract: Based on the working principle of a ferroelectric radiation detector and the response of the read out circuit, the electrical signal as a function of material properties and the wave-forms of radiation field was developed theoretically. A code based on GEANT4 was adopted to simulate the energy depositions of the CFBR-Ⅱ leakage neutrons and gammas in three typical ferroelectric materials, including lanthanum lead zirconate titanate PLZT ceramics, lithium tantalate single crystal, and polyvinylidene fluoride films, of which the theoretical properties as nuclear detectors were obtained. To detect the radiation field of the CFBR-Ⅱ reactor, the levels of sensitivity is approximately in the range of 10^-25~10^-27 C·m^-2, and results were confirmed by experiments. Although the polyvinylidene fluoride detector has the lowest sensitivity, it still have the potential to be used for fast neutron wave-from detections due to the singnal mainly contributed by neutrons.