The invention relates to a phosphor diffusion sheet luminaire for agricultural lighting, comprising: a lamp shell； a light source unit； a disc body, mounted in the accommodating space and gripped on the inner wall of the lamp shell, where the disc body is provided with plural tanks at the side corresponding to the light source unit, and the tanks are randomly filled with plural phosphors； and a diffusion sheet, mounted in the lamp shell, and the side of the diffusion sheet corresponding to the disc body. The light ray passing through the diffusion sheet will irradiate the plant. And the wavelength of the light ray varies according to different ratio of the phosphors. Adequate wavelengths are gained by means of light transmission, refraction and absorption, which is beneficial to control the growth of plant.
