The system identification method is used to establish the amplitude-frequency characteristic compensator of vibration velocity transducer for realizing low frequency vibration velocity measurement of a hydroelectric generating set.The amplitude-frequency characteristics of the reference model is used in this method as the ideal characteristics

according to measurement data of dynamic response of vibration velocity transducer

the parameter of the compensator is optimized by linear dynamic neuron（LDN） and error whitening criterion（EWC） for eliminating noise effect in the parameters estimation of compensator.Experimental results show that the approach is effective.