The invention provides a real-time video defogging system which belongs to the field of image processing and is characterized by being realized in a digital integrated circuit and comprising a data reading unit, a judgment unit, a sky brightness estimation unit, an atmosphere illumination white balance unit, an atmosphere dissipation image estimation unit and a clear scene recovery unit. As for the former K frames in the current lens of a video to be processed, the sky region thereof is estimated so that the sky brightness value is calculated; then the atmosphere illumination color of an image to be processed is corrected according to the sky brightness value by utilizing a white balance algorithm and a white balance image is normalized, the minimum values, minimum values of various colorcomponent are solved out so as to serve as rough estimated image; and based on the minimum values, an refined atmosphere dissipation image is calculated by utilizing an edge maintained flatting method, and the atmosphere scene albedo is calculated based on the atmosphere dissipation image, so that defogging recovery processing is carried out. As for a common-intermediate-format (CIF) video with the resolution of 288*352, the processing speed can be up to 60 fps (frames per second); and as for a D1-format video with the resolution of 578*720, the processing speed can be up to 15 fps, thus the system provided by the invention can be applied to monitoring systems and meet the requirement on real-time performance.