Abstract:Hankel matrix is combined with Singular Value Decomposition (SVD) for denoising the fault signal of gear using MATLAB software, in order to reduce noise in signals and improve Signal to Noise Ratio (SNR), so that to highlight the information feature of fault. The composed of measurement signal with noises of Hankel matrix was divided into two uncorrelated spaces, real signal space and noise space, and three different singular value selection methods respectively difference spectrum of singular value, mean value of eigenvalue and median of singular value were chosen to be applied, after processing the singular value matrix of two space, then reconstructed signal to reduce noise of measurement signal. The calculations and images show the denoising results of three different singular value selection methods, through which obtains that the median value of singular value method has the best denoising effect for broken teeth fault signal of gear.