Edge detection was an important step in image processing, in order to effectively suppressed noise and preserved edge information, analyzed the defects of Gauss filter was not adaptive, according to the characteristics of discontinuous noise gray value based on improved traditional mean filter, proposed a weighted mean filter coefficients adaptively, and through combined with LoG operator, a dual filter edge detection algorithm based on LoG operator was obtained. Compared with LoG operator and Canny operator, this algorithm has better detection accuracy while keeping the detection speed unchanged.