A diffusion sheet structure in the direct type backlight module with anti-UV rays function and its manufacturing method discloses a diffusion sheet in the backlight module applied to TFT-LCD TV, and plural layer of the diffusion sheet made by a method of a multi-layer co-extrusion. The diffusion sheet advocates that while producing diffusion layer, at least a ultra-violet rays absorption layer set on the surface of diffusion layer at the same time to achieve insulating ultra-violet rays directly irradiated on the diffusion sheet and to avoid yellow and pyrolysis phenomenon occurred on the diffusion sheet. These results in avoiding the deviation caused from color temperature and chromaticity coordinate of TFT-LCD TV because of yellow diffusion sheet, then to achieve the purpose of improving product quality and materials lifespan.