Abstract: Feature extraction of multi-component LFM signal based on Wigner-Hough transform is generally plagued by noises. Faced with this problem, the improved Sobel operator of digital image processing is used to detect edge features of Wigner-Ville distribution(WVD) figure of signals with noise, and then signal characteristics can be extracted well and truly under Hough transform. Through computer simulation of the Wigner-Hough transform(WHT), SPW D -Hough transform and improving WHT, feature extraction result of multi-component LFM signal using improved WHT proved to be the best.