The light trap on texture of silicon wafer surface makes the light reflect many times when it enters, and declines energy loss of light, and different structure of light trap produces different transmission path which makes a different effect of light reflectance. To study how structure of light trap and incident angle affect reflectance of light, a numerical method was proposed. Every light transmission process was tracked and then the weighted coefficient of reflectance of all lights was calculated. Subsequently the anti-reflection of complex texture with different incident angle was obtained, and a reasonable advice for change of process parameter was given, providing a theoretical basis for fabricating efficient texture. If the size of light traps is less than the wavelength of incident light, the reflection is specular, and the light trap is seen as smooth. Weighted coefficient of reflectance was got by calculating and analyzing different incident angle on light trap with aspect ratio, depth, and density of light trap, then ideal structure on fabric surface was proposed, and the incident angle with the best reflection effect was got. At the end, weighted coefficients of reflectance of two classic textures by alkaline corrosion and electrical discharge machining were calculated, and the validity of this method was proved by experimental measurement.