The invention relates to a dual energy X ray image display method in an HSL color space. The method comprises the steps that an HSL color space physical model is established; an organic substance, a mixture and an inorganic substance are selected; three substances of different volumes are taken to carry out data collection; the organic substance, the mixture and the inorganic substance of different volumes are used to prepare different substances; different substances are displayed in different colors; the colors displayed by the configuration substances cover all main colors in a color table; a color test box is designed, so that each step in the color test box represents a substance; and an HSL space color table is designed by adjusting H, S and L curves. According to the dual energy X ray image display method in the HSL color space, the characteristics of a security image are combined; the color table in the HSL space is designed; a user can adjust the configuration of H, S and L curves to enable different substances to display different colors; the color display of a displayed image is accurate; the overall image level is enhanced; and a local image is clear.