A new method was proposed for feature extraction from acoustic targets by combining wavelet packet characteristic energy operator with multi-kernel function combination Kernel Principal Component Analysis (KPCA). First, wavelet packet characteristic energy operator was used to the acoustic signal of target for extracting characteristic parameters. Then, the combined kernel function was used for KPCA. The experiment results show that:The characteristic feature extraction method proposed can reduce the dimensions of the feature parameters, improve recognition rate and decrease computation complexity.