Bearing early fault diagnosis method for multiple noise reduction processing

The invention discloses a bearing early fault diagnosis method for multiple noise reduction processing. The method comprises the following steps: collecting a vibration signal of a bearing; carrying out short-time Fourier transform on the bearing vibration signal, and preliminarily judging whether the bearing has a fault or not; adopting wavelet packet transformation to decompose and reconstruct the bearing vibration signal, and carrying out preliminary denoising; decomposing, screening and reconstructing the wavelet packet reconstruction signal by using an ensemble empirical mode decomposition method; eliminating aliasing interference signals contained in the reconstructed signals, and performing multi-layer noise reduction on the bearing vibration signal; carrying out demodulation processing on the reconstructed signal after noise reduction, and extracting a bearing fault frequency; and comparing with a theoretically calculated fault frequency, and diagnosing to obtain a fault conclusion of the bearing. Acc