Method for improving contrast ratio of reflection screen

According to the method for improving the contrast ratio of the reflection screen, the reflection screen comprises a front light source, a glass substrate, a color filter, an ITO coating, a reflection layer and a T-side glass substrate, the front light source, the glass substrate and the color filter are sequentially arranged above a liquid crystal layer in a laminated mode from top to bottom, and the color filter is close to the liquid crystal layer; the ITO coating, the reflecting layer and the T-side glass substrate are sequentially arranged below the liquid crystal layer in a laminated mode from top to bottom, and the ITO coating is close to the liquid crystal layer. The method comprises the steps that a black shading layer is arranged on the side, opposite to the reflecting layer, of the T-side glass substrate, and the black shading layer has the characteristic of being capable of absorbing light and converting the light into heat energy; the black shading layer is arranged on one side, opposite to the r