Embodiments of the present invention provide an image sharpening method and device. The method includes performing bilateral filtering processing and difference of Gaussians filtering processing on original image information to obtain first image-layer information and second image-layer information respectively. The first image-layer information is subtracted from the original image information to obtain third image-layer information. Fusion and superimposition processing is performed on the second image-layer information and the third image-layer information to obtain fourth image-layer information. The original image information and the fourth image information are added to obtain processed image information.