In the collection of local electrical signals, electrical equipment is in operation, and in the detection process, there will be a certain degree of noise interference, electromagnetic interference, or other interference. So the original signal received will be biased due to interference. Therefore, how to solve the noise processing of the original local emission electrical signals. In this paper, we thoroughly investigate noise reduction techniques based on wavelet threshold methods. We give an overview of wavelet theory and introduce the basic principle of the wavelet transform and its application in signal processing. In the experimental part, the methods of Dmey wavelet global default threshold denoising, Haar soft SUR threshold denoising, and DB3 wavelet fixed threshold are used to denoise and analyze the noise reduction effect under different threshold treatment methods.