Abstract: This paper proposes a new method for image enhancement of an X-ray screening image. Generally speaking, Image contrast of X-ray screening is smaller, the edge is not clear enough and noise of these image is unacceptable. the idea of this method is as follows:first, removing the noise of the background area of the security image, second, using the Laplace transform on the edge of the image,third, enhancing image contrast by CLAHE (local constrained histogram equalization), finally, using the bilateral filter to reduce image noise under the premise of maintaining the image edge. Such a combination method is perfect to correspond well to the characteristics of the traditional X-ray security screening images.