The invention discloses a video defogging method based on spectral clustering. The method specifically comprises the following steps: 1, acquiring, by a camera, a foggy video; 2, judging whether the current frame image Ik acquired in step 1 is a first frame image I1 of the video, if so, carrying out step 3, otherwise, carrying out step 4; 3, estimating global atmospheric light A for the first frame image I1, performing spectral clustering division, and calculating the transmittance of each cluster; 4, estimating the transmittance for video images from the second frame; and 5, recovering a frame of image according to the estimated global atmospheric light and transmittance. The video defogging method based on spectral clustering better ensures the spatial consistency of video frames, weakens the block effect of video images after defogging recovery, better ensures the continuity of video frames and avoids the scintillation effect among the video frames.