The invention discloses a fast superpixel segmentation method which is a top-down iterative segmentation method. The divisibility of the region is judged by analyzing the color consistency of the regional pixel set according to the method. The method comprises the following steps that step 1: the corresponding grayscale image I<Gray> of the original color image is acquired according to the formula(1); I<Gray>(x,y)=[I<R>(x,y)+ I<G>(x,y)+ I(x,y)]/3, wherein I<Gray>(x,y) refers to the pixel grayscale of the coordinates (x,y) on the image I<Gray>, I<R>(x,y) refers to the pixel grayscale of thecoordinates (x,y) on the image I<R>, I<G>(x,y) refers to the pixel grayscale of the coordinates (x,y) on the image I<G>, and I(x,y) refers to the pixel grayscale of the coordinates (x,y) on the image I; and I<R>, I<G> and I are the red, green and blue channel images of the original color image; and step 2: the superpixel region set S is calculated according to the grayscale image I<Gray>.