The frequency extraction of signal features is the critical key in vibration signal analysis. According to the actual conditions, vibration signal may consist of features of various noises. By preprocessing the signals with wavelet denoising, this paper enhances the signal SNR and improves the signal conditions. The signals after denoising process are decomposed in EMD algorithm, and several IMF components and residual components can be obtained. Finally, the frequency features are obtained after FFT frequency analysis on IMF components. It has been proved to be valid by simulation experiments.