In this paper, the failure features for electrical life prediction of AC contactor under mechanical vibration environment are studied, and a method based on optimized wavelet denoising and kernel principal component analysisPearson correlation coefficient methods is proposed to obtain effective failure features. Firstly, the life cycle tests for AC contactor were carried out under normal and vibration environment respectively, and several degradation parameters were selected as the analysis objects. Secondly, aiming at the measured data, the multiindex comprehensive evaluation method was used to optimize the wavelet denoising and then the degradation parameters were denoised and smoothed with the optimized method. Considering the degradation trend of the parameters, the influence of vibration on the electrical life of the AC contactor was analyzed. Finally, the full information features were constructed for the degradation parameters and their kernel principal components, and Pearson correlation coefficients between the features and the residual electrical life were calculated. In the vibration environment, using the proposed method the cumulative arcing energy, first kernel principal component, closing voltage and contact resistance are finally extracted as the failure features for electrical life prediction of AC contactor.