According to the sensitivity of pressure fluctuation amplitude related with the change of cavitation, the cavitation was first simulated on the centrifugal pump experimentation bed. It was found that the shaft frequency of the pump outlet pressure signal increase; many low frequencies appeared at the time of cavitation happening by using the outlet pressure signal. The natural state time serials model was established by the surface vibration and the outlet pressure signal of pump. Thus the state of centrifugal pump is distinguished and the feature extraction of cavitation is recognized by the variance of the model residual. 