Abstract: In order to overcome the difficulty of extracting the faint laser signal feature in foggy environment, a wavelet spatial correlation threshold filtering method was proposed based on the study of wavelet filtering algorithm. The idea and principle of the spatial correlation threshold filter were elaborated, and a method was studied particularly for filtering threshold selection. Comparing with spatial correlation filtering method, the new spatial correlation threshold filtering method shows better filtering effect for the faint laser signal in foggy environment. The experiments results in different fog density and different signal to noise ratio (SNR) show that, the spatial correlation threshold filtering can effectively rule out most of the noise and maintain weak laser signal characteristics. The spatial correlation threshold filtering method is more suitable for processing faint laser signal and feature extraction in fog media.